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Early on the morning of September 11,
2001, nineteen hijackers took control of four commercial airliners en route to San Francisco and Los Angeles from Boston,
Newark, and Washington, D.C. (Washington Dulles International Airport). At 8:46 a.m., American Airlines Flight 11 was crashed
into the World Trade Center's North Tower, followed by United Airlines Flight 175 which hit the South Tower at 9:03 a.m.
Another group
of hijackers flew American Airlines Flight 77 into the Pentagon at 9:37 a.m. A fourth flight, United Airlines Flight 93 crashed
near Shanksville, Pennsylvania at 10:03 a.m, after the passengers on board engaged in a fight with the hijackers. Its ultimate
target was thought to be either the Capitol (the meeting place of the United States Congress) or the White House.
In a September
2002 interview conducted by documentary-maker Yosri Fouda, an al Jazeera journalist, Khalid Sheikh Mohammed and Ramzi Binalshibh
stated that the fourth hijacked plane was heading for the United States Capitol, not for the White House. They further stated
that al-Qaeda initially planned to fly hijacked jets into nuclear installations rather than the World Trade Center and the
Pentagon, but it was decided not to attack nuclear power plants "for the moment" because of fears it could "get
out of control".
Some passengers were able to make phone calls using the cabin airphone service and mobile phones, and provide
details, including that several hijackers were aboard each plane, that mace or other form of noxious chemical spray, such
as tear gas or pepper spray was used, and that some people aboard had been stabbed. Reports indicated that during two of the
flights, the hijackers stabbed and killed aircraft pilots, flight attendants and in at least one case, a passenger. The 9/11
Commission established that two of the hijackers had recently purchased Leatherman multi-function hand tools. A flight attendant
on Flight 11, a passenger on Flight 175, and passengers on Flight 93 mentioned that the hijackers had bombs, but one of the
passengers also mentioned he thought the bombs were fake. No traces of explosives were found at the crash sites, and the 9/11
Commission believed the bombs were probably fake.
On United Airlines Flight 93, black box recordings revealed that crew and passengers attempted to
seize control of the plane from the hijackers after learning through phone calls that similarly hijacked planes had been crashed
into buildings that morning. According to the transcript of Flight 93's recorder, one of the hijackers gave the order
to roll the plane once it became evident that they would lose control of the plane to the passengers. Soon afterward, the
aircraft crashed into a field near Shanksville in Stonycreek Township, Somerset County, Pennsylvania, at 10:03:11 a.m. local
time (14:03:11 UTC). Khalid Sheikh Mohammed, organizer of the attacks, mentioned in a 2002 interview with Yosri Fouda that
Flight 93's target was the United States Capitol, which was given the code name "the Faculty of Law".
Three buildings
in the World Trade Center Complex collapsed due to structural failure on the day of the attack. The south tower (2 WTC) fell
at approximately 9:59 a.m., after burning for 56 minutes in a fire caused by the impact of United Airlines Flight 175. The
north tower (1 WTC) collapsed at 10:28 a.m., after burning for approximately 102 minutes.[28] When the north tower collapsed,
debris that fell on the nearby 7 World Trade Center (7 WTC) building damaged it and initiated fires. These fires burned for
hours and compromised the building's structural integrity, which led to the crumbling of the east penthouse at 5:20 p.m.
and to the complete collapse of the building at 5:21 p.m.
The attacks created widespread confusion among news organizations and air traffic controllers across
the United States. All international civilian air traffic was banned from landing on U.S. soil for three days. Aircraft already
in flight were either turned back or redirected to airports in Canada or Mexico. News sources aired unconfirmed and often
contradictory reports throughout the day. One of the most prevalent of these reported that a car bomb had been detonated at
the U.S. State Department's headquarters in Washington, D.C. Soon after reporting for the first time on the Pentagon crash,
some news media also briefly reported that a fire had broken out on the National Mall. Another report went out on the
Associated Press wire, claiming that a Delta Air Lines airliner—Flight 1989—had been hijacked. This report, too,
turned out to be in error; the plane was briefly thought to represent a hijack risk, but it responded to controllers and landed
safely in Cleveland, Ohio

After the 767 jet liner crashed
into the world trade center building creating the worst terror attack in history, a fire burned for 56 minutes inside the
World Trade Center building number two. The top 20 floors of the building collapsed on the 90 floors below. The entire one
hundred and ten-story building collapsed in 8 seconds... After a fire burned inside WTC tower number one for 102 minutes,
the top 30 floors collapsed on the lower 80 floors. And the entire one hundred and ten stories of this building collapsed
in 10 seconds. You can say the reason they collapsed was they were struck with a 185 ton jet airliner and
the 24,000 gallons of jet fuel caused a fire of 1500 to 2000 degrees F which weakened the steel and cause the collapse.
Or you can take a closer look at the buildings construction of the WTC buildings. And ask yourself why did these structures
collapse so fast and so completely. The answer can be found by examining high-rise construction in New York City
over the past 50 years World Trade
Center tower construction
In
terms of structural system the twin towers departed completely from other high-rise buildings. Conventional skyscrapers since
the 19th century have been built with a skeleton of interior supporting columns that supports the structure. Exterior walls
of glass steel or synthetic material do not carry any load. The Twin towers are radically different in structural design
as the exterior wall is used as the load-bearing wall. (A load bearing wall supports the weight of the floors.) The only interior
columns are located in the core area, which contains the elevators. The outer wall carries the building vertical loads and
provides the entire resistance to wind. The wall consists of closely spaced vertical columns (21 columns 10 feet apart) tied
together by horizontal spandrel beams that girdle the tower at every floor. On the inside of the structure the floor sections
consist of trusses spanning from the core to the outer wall. Bearing
walls and Open floor design
When
the jet liners crashed into the towers based upon knowledge of the tower construction and high-rise firefighting experience
the following happened: First the plane broke through the tubular steel-bearing wall. This started the building failure. Next
the exploding, disintegrating, 185-ton jet plane slid across an open office floor area and severed many of the steel interior
columns in the center core area. Plane parts also crashed through the plasterboard-enclosed stairways, cutting off the exits
from the upper floors. The jet collapsed the ceilings and scraped most of the spray-on fire retarding asbestos from the steel
trusses. The steel truss floor supports probably started to fail quickly from the flames and the center steel supporting
columns severed by plane parts heated by the flames began to buckle, sag, warp and fail. Then the top part of the tower crashed
down on the lower portion of the structure. This pancake collapse triggered the entire cascading collapse of the 110-story
structure. Steel Framing
The most noticeable change in the modern
high-rise construction is a trend to using more steel and shaping lightweight steel into tubes, curves, and angles to increase
its load bearing capability. The WTC has tubular steel bearing walls, fluted corrugated steel flooring and bent bar steel
truss floor supports. To a modern high rise building designer steel framing is economical and concrete is a costly material.
For a high-rise structural frame: columns, girders, floors and walls, steel provides greater strength per pound than concrete.
Concrete is heavy. Concrete creates excessive weight in the structure of a building. Architects, designers , and builders
all know if you remove concrete from a structure you have a building that weights less. So if you create a lighter building
you can use columns, girders and beams of smaller dimensions, or better yet you can use the same size steel framing and build
a taller structure. In News York City where space is limited you must build high. The trend over the past half-century is
to create lightweight high buildings. To do this you use thin steel bent bar truss construction instead of solid steel beams.
To do this you use hollow tube steel bearing walls, and curved sheet steel (corrugated) under floors. To do this you eliminate
as much concrete from the structure as you can and replace it with steel. Lightweight construction means economy. It
means building more with less. If you reduce the structure’s mass you can build cheaper and builder higher. Unfortunately
unprotected steel warps, melts, sags and collapses when heated to normal fire temperatures about 1100 to 1200 degrees F.
The fire service believes there
is a direct relation of fire resistance to mass of structure. The more mass the more fire resistance. The best
fire resistive building in America is a concrete structure. The structures that limit and confine fires best, and suffer fewer
collapses are reinforced concrete pre WWII buildings such as housing projects and older high rise buildings like the empire
state building, The more concrete, the more fire resistance; and the more concrete the less probability of total collapse.
The evolution of high- rise construction can be seen, by comparing the empire state building to the WTC. My estimate
is the ratio of concrete to steel in the empire state building is 60/40. The ratio of concrete to steel in the WTC is 40/60.
The tallest building in the world, the Petronas Towers, in Kula Lumpur, Malaysia, is more like the concrete to steel ratio
of the empire state building than concrete to steel ratio of the WTC. Donald Trump in New York City has constructed
the tallest reinforced concrete high-rise residence building.
Within 30 minutes of two planes hitting the World Trade Center twin towers, American Airlines Flight 77 departed
Dulles International Airport bound for Los Angeles. The Boeing 757 was hijacked and crashed, loaded with 10,000 gallons of
fuel, at 345 mph into the west side of the Pentagon. The five-story Pentagon is made up of five pentagonal structures arranged
in concentric rings. These rings surround a five-acre open courtyard and are connected by 10 spike-like corridors. The plane
took out light poles in the parking lot, hit the ground just outside the outermost ring of the Pentagon, turned up on its
wing, and penetrated the E ring (outermost) midway between corridors 4 and 5 as shown below. It then traveled through the
D ring and into the C ring. ll 58 passengers, four flight attendants, and both pilots on board, as well as 125 occupants of
the Pentagon, died. Although the blast from the plane and the toxic gas and heat from the resulting fire killed some people
in their offices near the crash site, some people working inside the Pentagon that morning did not know that a plane had hit
their building. Military and civilian personnel running up and down the corridors yelling for people to get out helped to
save a lot of lives. It was estimated that there were close to 2,600 people working in the Pentagon near the impact site.
The fact that so many people were able to survive speaks well to the design of Pentagon. Indeed, the building received many
upgrades following the Oklahoma City bombing to protect it from similar terrorist attacks. For instance, a recently completed
$258 million renovation to the west wing included Kevlar-reinforced windows. Despite the impact of the plane and the fires,
the damaged area did not collapse for 30 minutes, and the windows just next to the impact site remained intact, Shortly after the plane crashed into the Pentagon, the Arlington
County Fire 1 Department requested aid from the District of Columbia (DC) Fire/EMS Department. Because the incident
commander had a plane crash, building fire, terrorist attack, building collapse, and a crime scene all going on at once, the
District dispatched a second alarm 2 assignment to the Pentagon, along with several EMS units. A little less than an hour
later, Prince George's County Fire and EMS Department (PGFD) put out a call for all volunteer and career personnel to
report to their stations. Being a volunteer firefighter with Greenbelt's Volunteer Fire Department and Rescue Squad for
almost 6 years, I reported to my station. As units from DC were enroute to the Pentagon, the DC Fire Chief called back all
DC fire personnel. The Chief also requested mutual aid from Prince George's and Montgomery Counties Fire Departments to
fill in at stations in the Nation's Capital that were sent to the Pentagon. Shortly after 11:00 am, engines 3 from Greenbelt,
Morningside, Kentland, and Branchville and a truck 4 from Cottage City were transferred into the District. Greenbelt's
Chief, Assistant Chief, six other personnel, and I filled in at DC Engine 8 (1520 C Street) in southeast DC. Because we were
not familiar with southeast DC, an officer from Station 8 rode with us on our engine. Shortly before 12:30 pm, we ran a hazardous
materials call at a local high school. Enroute to the call, we could not help but wonder if this was part of the terrorist
attack. We cleared the call almost 30 minutes later. Just after 1:00 pm, the DC Fire Department's Pentagon Command requested
a third alarm. As we were heading back to Station 8 in the District, we were informed that we were being transferred to another
DC fire station. Arriving at Station 8, we dropped off the officer who was riding with us. Just as we were about to leave,
he ran out telling us that we were the first due on the third alarm at the Pentagon.
All transferred companies
from PG were placed on the third alarm. As we were driving down the freeway responding to the Pentagon, it looked like a war
zone—military vehicles and busses carrying personnel, police cruisers, and Red Cross and other disaster vehicles all
rushing past; helicopters in the air; and not an airplane or passenger vehicle in sight. When we arrived at the Pentagon,
we stood by in the south parking lot so that we could meet with DC fire officials and review the plan of attack.

Because the access tunnel leading underneath the Pentagon
to the inside courtyard was only 10-foot 2-inch high, many of the towers and ladder trucks that were to go to the courtyard
to put water on the roof were too tall to fit through the tunnel. Therefore, some of these apparatus had their roofs cut off
so that they would fit through the tunnel. While the first and second alarms were attacking the fire from the exterior of
the outer ring, at 1:25 pm, the third alarm units proceeded through the tunnel into the inner courtyard. The idea was to attack
the fire from inside the Pentagon, pushing it from the unburned areas back into the burnt areas.
What we found
when we entered the inner courtyard was unbelievable. Large groups of military and emergency room doctors were milling about
waiting for survivors to be brought out of the building. Parts of the airplane and building were thrown about the courtyard
and marked with evidence flags. FBI and other federal officials were walking around conducting their investigation. Members
of the military were standing by at a makeshift morgue with body bags waiting for the fires to be put out so that search-and-rescue
crews could go in and recover bodies of the victims. Over 35 agencies responded to the Pentagon that day.
There
was a lot of misinformation that moved across the courtyard, and we felt very isolated from the events that were going on
outside the walls of the Pentagon — reports of thousands of civilians and 500 firefighters feared dead at the collapse
of the World Trade Center towers, a plane crashing into Camp David, a bomb exploding at the State Department, and that the
military had information that 50 other targets were to be hit that day. Although some believed that there was the possibility
of additional terrorist attacks on the Pentagon, we knew all we could do was focus on the task at hand.
Shortly
after 2:00 pm, our first task was to stand by outside the B ring while the Arlington Fire Department attempted to make entry
to the first floor between corridors 4 and 5. The fire was too intense and the crew quickly retreated.
Around 3:00
pm, the units from Prince George's County were then given the unenviable task of taking the first interior attack line
into the C ring of the second floor of the Pentagon with the express orders to search for survivors and extinguish what fire
we could. It had been determined that this was the area most likely to have survivors. If no survivors were found, extinguishing
the fires would allow search-and-rescue crews to follow behind and begin to recover bodies. A 4" supply line (yellow
in the picture below) was laid by the Arlington County Fire Department from outside the Pentagon into the inner courtyard.
We entered corridor 5 and proceeded to the second floor of the C ring, stretching a 3" line (tan in the picture below)
from an engine from Branchville. My task was to carry one of two 1-3/4" attack lines (red in the picture below) that
were to be deployed to attack the fires. We advanced the supply line approximately 200 feet down the first floor of Corridor
5 through the A ring, into the B ring, and up an interior stairwell to the second floor. Once crews reached the second floor,
the 3" supply line was stretched another 200 feet into the C ring. At that point, I hooked up one of the two attack lines
and our crew made an attempt to extinguish the fires on the second floor.
It was on Tuesday, September 11, 2001.
That was the worst disaster in American history. The whole country was in sadness. When the World Trade Center was struck by terrorists,
it was about eight forty eight in the morning. When everyone was at work or about to get there, the enemy struck and in doing
so, took the
lives of so many people. It was so sad because I was on my way to work myself, going to Manhattan when this disaster took
place. It was very sad to me because it could have been someone in my family on that plane too. But it felt like a part of me was struck
because a lot of my friends that I have made in this country. So it pains me to see that so many of my friends have lost their loved ones
in this disaster. It is sorrowful to see so much grief and hurt. It is not easy to be in their shoes. It is not a nice feeling but none-the-less
God is in everything and He knows the best for our lives. I am not only saying so because I know that God will help us all
in the end. Mervyn
Clement
There is no single, universally accepted,
definition of terrorism. The U.S. Code and the FBI define terrorism as “...the unlawful use of force or violence against
persons or property
to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social
objectives.”

During calendar year 1997, the FBI recorded
two terrorist incidents (neither of which resulted in injuries) and two suspected acts of terrorism on U.S. soil (both of
which resulted in injuries). Within the same year, 21 potential acts of terrorism were prevented in the United States—the
highest number of preventions recorded since 1985, when 23 planned acts of terrorism were prevented. Meanwhile, the U.S. Government brought
several high-profile terrorists to justicein 1997. On June 2, 1997, Timothy McVeigh was convicted of the April 1995 bombing
of the Alfred P. Murrah Federal Building in Oklahoma City. On August 14, McVeigh was sentenced to death for carrying out the
most deadly act of terrorism in U.S. history. McVeigh’s accomplice in the attack, Terry Lynn Nichols, was convicted
of conspiracy and involuntary manslaughter on December 23, 1997, and as of the end of the year was awaiting sentencing. On
November 12, 1997, international terrorists Ramzi Ahmed Yousef and Eyad Mahmoud Ismail Najim were found guilty of conspiracy
for their roles in the 1993 bombing of the World Trade Center. Both suspects had fled the United States shortly after the
bombing, but
were apprehended and returned to stand trial in the Southern District of New York.

Ewen Wilson U.S. Census Bureau September,
2001 To concerned family and friends, a brief personal account: Sept 11, 2001 dawned bright and clear in New York.
I telephoned Cindy from my room in the World Trade Center Marriott to wish her a happy birthday before heading down to a breakfast
meeting to hear a speech by the President of Morgan Stanley, Robert Scott. Not long into his remarks, what sounded like an
massive explosion shook the building, the ballroom chandeliers tinkled violently and after a few stunned seconds people jumped
up and rushed for the exits. In the hotel lobby we were directed out of the southern end of the hotel to Liberty Street to
avoid the debris raining down onto West Street. We headed west for the Hudson River, and looking back over our shoulders could
see a gaping hole high up on WTC tower 1 from which flames were raging. The horror was driven home as we saw the first of
several bodies hurtling down from high in the building. I joined a colleague, Bob Parker, with a cell phone and asked him
if I could call my office to let them know we were out of the building, but the phone was inoperable. We headed South down
the bank of the river in search of a pay phone. No sooner had we got into a queue for the phone when the second plane flew
into WTC 2 with a mighty explosion. This is when we realized that this was no accident, but we were witnessing a terrorist
attack. We decided to continue our phone search at a further distance and soon found success in a parking garage where I contacted
my office and asked them to let Kay and Cindy know that I was ok. After this Bob and I discussed what to do next. He decided
to head uptown to catch a train to Washington from Penn Central. I thought that the trains would not be running and opted
to head to the rental car facilities at La Guardia airport, hoping to rent a car to drive home. Traffic at this point
was stalled and hundreds of thousands of people were milling around, but moving in a general south-east direction towards
FDR Drive on the East River. Someone told me that the Pentagon had been attacked, filling me for the first time with real
panic. I did not know if Cindy was at work, and as it turned out was unable to make contact with her until I reached Hertz
at La Guardia. As I was crossing Broadway, WTC 2 imploded and collapsed with huge roar. A massive wall of ash and debris came
rushing down the street at us, like a huge tidal wave with people fleeing ahead of it, covering us in dust and making it difficult
to breath. Luckily I had been able to get a face mask from one of the firefighters which helped, but other people used coats,
shirts etc around their faces. I found myself in a large and mostly orderly crowd heading for the Brooklyn Bridge. As we started
over the bridge, WTC 1, the north tower collapsed, changing dramatically the face of lower Manhatten. Once over the bridge
in Brooklyn it became clear that there were no cabs available, so I was forced to hitch a ride from a big-hearted off-duty
female cop, and then hire a robber limousine driver to take me to Hertz. That is where, to my great relief I was finally able
to make contact with Cindy.As it turned out there were no rental cars left but I was able to pair up with another good Samaritan,
and by extraordinary coincidence eventually join up with Brian (my brother-in-law, a KPMG partner who works on their Bank
One account) who just happened to be in New Jersey on a business trip from Chicago. We drove together back to Falls Church,
and after a nights rest, Brian continued driving to Chicago rather than wait for airports to reopened The TV this morning
shows ghastly scenes of the staggering damage to lower Manhatten - a war zone. The Pentagon was still smoking as I drove over
the 14th Street bridge to work. But traumatic as it may have been for us, many more people face personal tragedy. Thousands
of people died. We, thank God, are the fortunate ones, even though it will be hard to erase some awful images from the mind. Thank you for your loving messages of concern.

There were a total of 2,996 deaths,
including the 19 hijackers and 2,977 victims. The victims were distributed as follows: 246 on the four planes (from
which there were no survivors), 2,606 in New York City in the towers and on the ground, and 125 at the Pentagon. All the deaths
in the attacks were civilians except for 55 military personnel killed at the Pentagon.
More than 90 countries lost citizens in the
attacks on the World Trade Center. In 2007, the New York City medical examiner's office added Felicia Dunn-Jones to the
official death toll from the September 11 attacks. Dunn-Jones died five months after 9/11 from a lung condition which was
linked to exposure to dust during the collapse of the World Trade Center.[46] Leon Heyward, who died of lymphoma in 2008,
was added to the official death toll in 2009.[47]
NIST estimated that about 17,400 civilians were in the World Trade Center complex at the time of
the attacks, while turnstile counts from the Port Authority suggest that 14,154 people were typically in the Twin Towers by
8:45 a.m. The vast majority of people below the impact zone safely evacuated the buildings, along with 18 people who were
in the impact zone in the south tower and a number above the impact zone who evidently used the one intact stairwell in the
south tower. At least 1,366 people died who were at or above the floors of impact in the North Tower and at least 618 in the
South Tower, where evacuation had begun before the second impact. Thus over 90% of the workers and visitors who died in the
Towers had been at or above impact.
According to the Commission Report, hundreds were killed instantly by the impact, while the rest
were trapped and died after tower collapse. At least 200 people jumped to their deaths from the burning towers (as depicted
in the photograph "The Falling Man"), landing on the streets and rooftops of adjacent buildings hundreds of feet
below. Some of the occupants of each tower above its point of impact made their way upward toward the roof in hope of helicopter
rescue, but the roof access doors were locked. No plan existed for helicopter rescues, and on September 11, the thick smoke
and intense heat would have prevented helicopters from conducting rescues.
A total of 411 emergency workers who responded to
the scene died as they attempted to rescue people and fight fires. The New York City Fire Department (FDNY) lost 341 firefighters
and 2 FDNY paramedics. The New York City Police Department lost 23 officers. The Port Authority Police Department lost 37
officers, and 8 additional EMTs and paramedics from private EMS units were killed.
Cantor Fitzgerald L.P., an investment bank
on the 101st–105th floors of One World Trade Center, lost 658 employees, considerably more than any other employer.
Marsh Inc., located immediately below Cantor Fitzgerald on floors 93–101 (the location of Flight 11's impact), lost
355 employees, and 175 employees of Aon Corporation were killed. After New York, New Jersey was the hardest hit state, with
the city of Hoboken sustaining the most deaths.
Weeks after the attack, the number of deaths was estimated to be over 6,000, but this turned out
to be more than twice the number of actual confirmed dead. The city was only able to identify remains for about 1,600 of the
victims at the World Trade Center. The medical examiner's office also collected "about 10,000 unidentified bone and
tissue fragments that cannot be matched to the list of the dead". Bone fragments were still being found in 2006
as workers were preparing to demolish the damaged Deutsche Bank Building. That operation was completed in 2007. On April 2,
2010 a team of anthropology and archaeological experts began searching for human remains, human artifacts and personal items
at the Fresh Kills Landfill on Staten Island. The operation was completed in June 2010 with 72 human remains found, bringing
the total human remains found to 1,845. The identities of 1,629 of the 2,753 victims have been identified. DNA profiling
in an attempt to identify additional victims is continuing

Effects of jet crash and fire on a skeleton
steel high rise A plane that only weighted 10 tons struck the Empire State Building and the high-octane gasoline fire
quickly flamed out after 35 minutes. When the firefighters walked up to the 79 floor most of the fire had dissipated. The
Empire State Building in my opinion, and most fire chiefs in New York City, is the most fire safe building in America. I believe
it would have not collapsed like the WTC towers. I believe the Empire State Building, and for that matter any other skeleton
steel building in New York City, would have withstood the impact and fire of the terrorist’s jet plane better than the
WTC towers. If the jet liners struck any other skeleton steel high rise, the people on the upper floors and where the jet
crashed may not have survived; there might have been local floor and exterior wall collapse. However, I believe a skeleton
steel frame high rise would not suffer a cascading total pancake collapse of the lower floors in 8 and 10 seconds. Hopefully
some engineer using computer calculations, can reconstruct the effects of a 767 jetliner crashing into another New York City
high building. In any other high rise in New York City, I say, the floors below the crash and fire, would not collapse in
such a total a cascading pancake cave-in. Most of the occupants and rescuers killed in the WTC tower collapse were on
the lower floors. The Empire State Building
Perhaps builders should take a second look at the Empire State
Buildings construction. There might be something to learn when they rebuild on ground zero. The empire state building has
exterior Indiana limestone exterior wall, 8 inches thick. The floors are also 8 inches thick consisting of one-inch cement
over 7 inches of cinder and concrete. All columns, girders and floor beams are solid steel covered with 1 to 2 inches
of brick terracotta and concrete. There is virtually no opening in the floors. And there are no air ducts of a HVAC
heating cooling and venting system penetrating fire partitions, floor, and ceilings. Each floor has its own HVAC unit. The
elevators and utility shafts are masonry enclosed. And for life safety there is a 4-inch brick enclosed so-called “smoke
proof stairway”. This stairway is designed to allow people to leave a floor without smoke following them and filing
up the stairway. This is accomplished because this smoke proof stairway has an intermediate vestibule, which contains a vent
shaft. Any smoke that seeps out the occupancy is sucked up a vent shaft. Concrete removal
Since the end of
WWII builders designed most of the concrete from the modern high-rise constriction. First concrete they eliminated was the
stone exterior wall. They replace them with the “curtain walls of glass, sheet steel, or plastics. This curtain wall
acted as a lightweight skin to enclose the structure from the outside elements. Next the 8-inch thick concrete floors went.
They were replaced with a combination of 2 or 3 inches of concrete on top of thin corrugated steel sheets. Next the masonry
enclosure for stairs and elevators were replaced with several layers of sheet rock. Then the masonry smoke proof tower
was eliminated in the 1968 building code. It contained too much concrete weight and took up valuable floor space. Then
the solid steel beam was replace by the steel truss. And finally the concrete and brick encasement of steel columns girders
and floor supports was eliminated. A lightweight spray-on coating of asbestos or mineral fiber was sprayed over the
steel. This coating provided fireproofing. After asbestos was discovered hazardous vermiculite or volcanic rock ash substance
was used as a spray-on coating for steel. Outside of the foundation walls and a thin 2 or 3 inches of floors surface, concrete
has almost been eliminated from high-rise office building construction. If you look at the WTC rubble at ground zero you see
very little concrete and lots of twisted steel.

At 8:46 on the morning of September
11, 2001, the United States became a nation transformed. An airliner traveling at hundreds of miles per hour and carrying
some 10,000 gallons of jet fuel plowed into the North Tower of the World Trade Center in Lower Manhattan. At 9:03, a second
airliner hit the South Tower. Fire and smoke billowed upward. Steel, glass, ash, and bodies fell below.The Twin Towers, where
up to 50,000 people worked each day, both collapsed less than 90 minutes later. At 9:37 that same morning, a third airliner
slammed into the western face of the Pentagon. At 10:03, a fourth airliner crashed in a field in southern Pennsylvania. It
had been aimed at the United States Capitol or the White House, and was forced down by heroic passengers armed with the knowledge
that America was under attack. More than 2,600 people died at the World Trade Center; 256 died on the four planes. The death
toll surpassed that at Pearl Harbor in December 1941. This immeasurable pain was inflicted by 19 young Arabs acting at the
behest of Islamist extremists headquartered in distant Afghanistan. Some had been in the United States for more than a year,
mixing with the rest of the population. Though four had training as pilots, most were not well-educated. Most spoke English
poorly, some hardly at all. In groups of four or five, carrying with them only small knives, box cutters, and cans of Mace
or pepper spray, they had hijacked the four planes and turned them into deadly guided missiles.
The 9/11 attacks were a shock, but they
should not have come as a surprise. Islamist extremists had given plenty of warning that they meant to kill Americans indiscriminately
and in large numbers. Although Usama Bin Ladin himself would not emerge as a signal threat until the late 1990s, the threat
of Islamist terrorism grew over the decade. In February 1993, a group led by Ramzi Yousef tried to bring down the World Trade
Center with a truck bomb.They killed six and wounded a thousand. Plans by Omar Abdel Rahman and others to blow up the Holland
and Lincoln tunnels and other New York City landmarks were frustrated when the plotters were arrested. In October 1993, Somali
tribesmen shot down U.S. helicopters, killing 18 and wounding 73 in an incident that came to be known as “Black Hawk down.”Years
later it would be learned that those Somali tribesmen had received help from al Qaeda. In early 1995, police in Manila uncovered
a plot by Ramzi Yousef to blow up a dozen U.S. airliners while they were flying over the Pacific. In November 1995, a car
bomb exploded outside the office of the U.S. program manager for the Saudi National Guard in Riyadh, killing five Americans
and two others. In June 1996, a truck bomb demolished the Khobar Towers apartment complex in Dhahran, Saudi Arabia, killing
19 U.S. servicemen and wounding hundreds.The attack was carried out primarily by Saudi Hezbollah, an organization that had
received help from the government of Iran.

Who is this enemy that created an organization
capable of inflicting such horrific damage on the United States? We now know that these attacks were carried out by various
groups of Islamist extremists.The 9/11 attack was driven by Usama Bin Ladin. In the 1980s, young Muslims from around the world
went to Afghanistan to join as volunteers in a jihad (or holy struggle) against the Soviet Union. A wealthy Saudi, Usama Bin
Ladin, was one of them. Following the defeat of the Soviets in the late 1980s, Bin Ladin and others formed al Qaeda to mobilize
jihads elsewhere. The history, culture, and body of beliefs from which Bin Ladin shapes and spreads his message are largely
unknown to many Americans. Seizing on symbols of Islam’s past greatness, he promises to restore pride to people who
consider themselves the victims of successive foreign masters. He uses cultural and religious allusions to the holy Qur’an
and some of its interpreters. He appeals to people disoriented by cyclonic change as they confront modernity and globalization.
His rhetoric selectively draws from multiple sources—Islam, history, and the region’s political and economic malaise. Bin Ladin also stresses grievances against the United States widely shared in the Musliast.m world. He inveighed against the presence of U.S. troops in Saudi
Arabia, which is the home of Islam’s holiest sites, and against other U.S. policies in the Middle East

Around 8:43 a.m. I was at home having
breakfast when a friend called me to ask if I knew what happened to the Twin Towers. I said no. I turned on my T.V. and only
Channel two was working. The news reporter said that two airplanes crashed into the Twin Towers. It was like a movie to me.
I could not believe that was real. So I called my friend who worked close to the Twin Towers and she was okay. But then she
told me her daughter goes to school close by that area. She did not hear from her yet because cell phones were not working.
Then I started to believe that New York was under attack. I got down on my knees and I prayed, asking the Lord to have mercy
upon us and watch over us from all these evil doers. As the day passed by, I started to hear the amount of dead people and
I saw pictures
of the Tower. My heart felt sore and will take a long time to heal. Terrorists changed America for life. It left children
without mother and father. Also because of the tragedy there are wives without husbands and husbands without wives. Oh how
sad. America must go on. God bless America. Mary Baptiste
Tuesday, September 11, 2001. I woke
up at 6:30 A.M. I help my teacher every morning to set up the tables, chairs, clean the board. Everybody sat down, and listened
to the teacher. Later, after one hour of class, the door was opened, the pastor brought the TV and plugged it in. He said
to us "Something bad happened. I think it was an explosion near the World Trade Center" and then he turned on the
TV. We couldn’t see it clearly. At that moment nobody knew anything, but we talked to each other and asked, what happened.
Something serious was going on. I remember this word "Unconfirmed." There was an unconfirmed report of a hijacked
American Airlines 767 plane from Boston. It is possible there were passengers on board, they said. There was confusion about
what was going on. Everybody asked. Nobody knew. We cried for hours, days, weeks, and let me tell you something. I'm still
crying. TV, radio, newspapers, had the impact news. The news changed our life forever. The news that sent a lot of people
to the hospitals. The news that buried many, many people. Innocent people, good people, hard working people, and responsible
people. They didn't deserve that. For me it's a nightmare, believe me. Many people feared that this might happen again.
The U.S. sent soldiers to Afganistan. My son was prepared when the military called him. I pray to God that nothing bad will
happen, I pray for those people that are suffering the loss of their family. My heart is with them. I remember that Prokopi
(another student) was crying because some of his family worked in the World Trade Center. When my husband came to school,
we looked at each other and cried. I saw people running across the street, the ambulances, the police, it looked like a movie.
Everybody was confused. God bless all of you. God Bless America, Land of the Free, Home of the Brave. America won't forget. Margarita Lugo

I am Muslim, and I am from Bangladesh.
Now I am going to express myself about how much the September 11th incident hurt me. I can't imagine how I got through
that day. I was so anxious about my husband, brother, and children. At last they came back home. My heart is filled with sorrow,
because some parents lost their son or daughter, some children lost their parents, some wives lost their husbands, some husbands
lost their wives, and some friends were lost also. I always pray to God for all of those innocent people. I pray for the forgiveness
of their souls. I saw that picture of destruction on the TV. I also read the newspaper, and received some messages like some
Muslim women were harassed by people of other religions. At that time to go outside was intolerable for me. There was not
a single person who didn't look around me. Almost everybody blamed me, used street language, called me crazy. Some Muslim
women avoided wearing scarves. Right now this discrimination is still going on. I don't know when this insufferable situation
will calm down and when peace will be everywhere. Monoara Begum

I was on the 13th floor of the World Trade Center Marriott
Hotel when the first plane hit the North Tower. I was getting ready in the hotel room to head for work at 50 Broad Street,
a few blocks from the World Trade Center. It seemed like a regular day on the morning of Sept 11, 2001. All of a sudden, I
heard an immense explosion. The explosion was so powerful, it rocked the building and my entire room shook. I did not know
what it was. I thought it might have been an earthquake or a construction accident. I ran out to the hallway to find some
news & saw no one.
I called the
front desk - lines were busy. I finally looked out the window - what I saw was unimaginable horror. Fiery debris was raining
outside my window. I saw a blizzard of glass, paper, debris and chunks of metal avalanching to the ground into the plaza between
the two towers. The explosion had sent burning debris & glass to the plaza below. I saw scores of people running for cover.
I saw other people collapse as they were hit by flying debris. I was shocked and horrified as I watched from my room as people
ran for their lives, got hit by debris and were injured or killed. More thunderous explosions erupted as additional large
chunks of building fell outside my window & came plummeting down to the plaza. Pieces of metal the size of couches fell
right in front of my eyes as I looked on in horror. I became terrified the debris would crash right into my room so I ran
to the bathroom. My heart was racing - I thought my life was over. I heard a woman in the hallway yell, "Get out of the
building!" I went out the hallway & saw a tall blond woman yelling, "Get out of here!" Some people started
coming out of their rooms, confused. At this point, I still didn't know what was happening but I grabbed my wallet, phone
& went to the nearest stairway. Only a few others followed. The tall blond woman kept stopping on each floor to warn others.
I asked her what was going on. She just kept screaming, "Get out of the building!"
I continued my way down the stairs & was the first to reach
the first floor. The only exit on the first floor was a glass door leading to the plaza. Unfortunately, it lead to the plaza
between the twin towers where it was still avalanching thick dust, paper, glass shards & metal chunks - we couldn't
leave through that door or we would have been killed by the falling debris. Fear consumed me for a few seconds with the thought
of not being able to get out of the building. I went back up the stairs. I took a chance & got off on the 3rd floor &
luckily, it was the hotel lobby. A security personnel was directing people out. Along with numerous of other people, I walked
out the building. The first person I noticed outside was a police officer. He screamed at us,"Get out of this area &
don't look up!"
"Get
out of the area and don't look up, get out of the area-don't look up "- these words rang in my ears as I walked
away. I tried to use my cell phone but all connections were busy. As I crossed the street, I turned around & looked up
at the World Trade Center - unspeakable horror loomed above me. Flames were bellowing out from the top floor windows of the
first tower. I watched in shock as the World Trade Center burned. It was an inferno. I felt a wave of sadness as I realized
all the people in those top floors were burning and dying. Then, I saw bodies coming out the windows & falling to the
ground. People stopped & stared and could not peel their eyes away from the scene. For me, the carnage in the plaza earlier
in addition to the falling bodies from the building was too much to handle. I looked away & kept walking. I couldn't
bear to look anymore at the looming death all around me. As I walked, a large plane flew over me. For a second, I felt relieved
because I thought it was the US military Air Force making its way to rescue the people in the burning tower. Then I heard
people wondering why a passenger plane would be flying this low towards the World Trade Center. That was when I heard a deafening
crash in the sky - the plane had crashed into the second tower. The ground seem to shake with the crash. The streets were
filled with screams and everyone started running. It felt like the end of the world.
I was scared for my life. I started running and looking frantically for cover.
Everyone was running for cover - behind cars, in buildings. I ran so fast, I dropped my credit cards from my wallet. A man
with a British accent picked up my credit cards, ran after me to give them back. I knew I needed to get underground. I ran
and ran, sometimes it seem in circles. I ran until I came to a subway station. I got on the No. 5 train at Bowling Green.
In the train, I met a man whose eyes were damaged from the flying debris. He just wanted to go home and see a doctor to treat
his eyes. It was only at that point, in the subway on the No. 5 train going uptown that I found out the towers were attacked
by hijacked planes taken over by terrorist. It has been 3 days since this horrific event.
It took several hours after the attack for the trembling to stop & my heart
to return to a normal rate. I am never going to forget what I saw - the images of carnage & people dying are etched in
my brain. I have not been able to sleep peacefully without hearing the screams and the explosion & seeing the carnage
in my head. I cry when I watch the news. I left behind my luggage in the hotel - it is now covered in the ruins of the World
Trade Center collapse. Buried in the rubble are my luggage, my clothes, my backpack, my laptop & notebooks. I lost these
items in this horrible event. However, I am grateful that these items are the only thing I lost - I did not lose my life.
I am grateful to the tall blond woman who adamantly
went to every floor yelling for everyone to get out of the building. I am grateful for the British man in the suit who picked
up my credit cards & ran after me to give it back. I am thankful for Marriott Marquis who allowed me into their ballroom
shelter with the rows of rollaway beds after being refused by a dozen hotels & after wandering the NY streets for 8 hours
looking for a place to stay. I am grateful for the people on 49th street who hugged me & asked if I needed money or help
after hearing my story. Peace to the survivors. My heart goes out to everyone who has lost or is missing loved ones.
Joyce Ng 9/14/01

A decade of conflict in Afghanistan, from 1979 to 1989,
gave Islamist extremists a rallying point and training field.A Communist government in Afghanistan gained power in 1978 but
was unable to establish enduring control.At the end of 1979, the Soviet government sent in military units to ensure that the
country would remain securely under Moscow’s influence. The response was an Afghan national resistance movement that
defeated Soviet forces. Young Muslims from
around the world flocked to Afghanistan to join as volunteers in what was seen as a “holy war”—jihad—against
an invader.The largest numbers came from the Middle East. Some were Saudis, and among them was Usama Bin Ladin. Twenty-three
when he arrived in Afghanistan in 1980, Bin Ladin was the seventeenth of 57 children of a Saudi construction magnate. Six
feet five and thin, Bin Ladin appeared to be ungainly but was in fact quite athletic, skilled as a horseman, runner, climber,
and soccer player. He had attended Abdul Aziz University in Saudi Arabia. By some accounts, he had been interested there in
religious studies, inspired by tape recordings of fiery sermons by Abdullah Azzam, a Palestinian and a disciple of Qutb.Bin
Ladin was conspicuous among the volunteers not because he showed evidence of religious learning but because he had access
to some of his family’s huge fortune.Though he took part in at least one actual battle,he became known chiefly as a
person who generously helped fund the anti-Soviet jihad.
Finally, Bin Ladin had another advantage: a substantial,
worldwide organization. By the time he issued his February 1998 declaration of war, Bin Ladin had nurtured that organization
for nearly ten years. He could attract, train, and use recruits for ever more ambitious attacks, rallying new adherents with
each demonstration that his was the movement of the future.

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