Pictures from 9/11: Attack on Architecture

What Happened When?

top of burning, flaming modern skyscrapers near an older building
Twin Towers Aflame on September 11, 2001. Carmen Taylor/Getty Images (cropped)

On September 11, 2001, a date that has become known as one of the scariest days in U.S. history, terrorists flew commercial jets into three American buildings. What structures were involved that fateful morning? As shown in this September 11 photo timeline, the carnage began in Lower Manhattan, with two prominent skyscrapers.

The World Trade Center Towers Before the Attack

new york city skyline before the twin tower skyscrapers were destroyed on 9/11
World Trade Center Twin Towers and the New York City Skyline Before the September 11, 2001 Terrorist Attack. Carol M. Highsmith/Buyenlarge/Getty Images (cropped)

Built in the 1970s, the World Trade Center (WTC) twin towers in New York City were designed to withstand normal fires and hurricane-force winds. According to some reports, engineers believed that even the impact of a Boeing 707 would not bring down the towers.

But no engineer could have prepared for the destruction caused on 9/11 when terrorists hijacked two passenger jets, each much larger than a Boeing 707, and slammed them into the WTC towers. WTC 1, known as "the north tower" was located geographically north of WTC 2, or "the south tower." The north tower was hit first, from aircraft originating in Boston, Massachusetts.

8:46 a.m. - Commercial Jet Hits the WTC North Tower

top of box-like skyscraper with flames and smoke -- The north tower of the World Trade Center burns after s hijacked airplane hit it September 11, 2001 in New York City.
The North Tower Hit First on 9/11. Jose Jimenez/Primera Hora/Getty Images (cropped)

On September 11, 2001 at 8:46 a.m. Eastern time, five terrorists took control over a Boeing 767 jet, American Airlines Flight 11 from Boston, Massachusetts, and maneuvered the hijacked aircraft into the north tower, WTC 1, of the World Trade Center Complex of buildings in New York City.

At a speed of 440 mph, the plane punctured the tower at floors 94 through 98. The 110-story skyscraper was not immediately destroyed. Emergency responders rushed to the scene of what many thought to be a horrible accident with a commercial airliner.

Smoke Fills the WTC North Tower

detail of smoke and people from the windows of a grey stone skyscraper
The North Tower of the World Trade Center on 9/11. Jose Jimenez/Primera Hora/Getty Images (cropped)

Debris from the aircraft sliced through the core of the World Trade Center north tower. The elevator shaft — really a big, empty tube in the middle of the skyscraper — became a conduit or channel for burning jet fuel, like a huge hose. As smoke billowed from the upper floors, countless people leaned from the windows, waiting for help. Doors to the roof had remained locked for safety and security.

The evacuation of the south tower next door was not immediately called for. People were just arriving to work and trying to comprehend the bedlam of what at first was considered an accident.

9:03 a.m. - Hijacked Plane Hits the WTC South Tower

tops of two skyscrapers, explosive flames on the left one and billowing black smoke on the right one
A Fiery Blast Rocks the South Tower. Spencer Platt/Getty Images (cropped)

At 9:03 a.m. ET, hijacked United Airlines Flight 175, also originating from Boston's Logan Airport, crashed into the south side of the south tower at a speed of 540 mph — much faster than the first aircraft. Both skyscrapers within the trade center site in Lower Manhattan were burning from the jet fuel stored on each aircraft that had been scheduled to fly to Los Angeles.

The second plane, a Boeing 767 jet, burst into flames as it struck floors 78 through 84 — lower in the building than the aircraft that crashed into WTC 1. Like the first jet into tower one, the impact on tower two destroyed support columns but did not cause the immediate collapse. Both skyscrapers stood tall and burning.

9:37 a.m. - The Pentagon Hit Near Washington, D.C.

Smoke comes out from the the Pentagon building, a low structure with the Washington Monument in the background, after a plane crashed into the building and set off a huge explosion
The Pentagon Near Washington, D.C. on September 11, 2001. Alex Wong/Getty Images

Less dramatic but perhaps more significant was the terror attack on the headquarters of the United States Department of Defense near Washington, D.C. At 9:37 a.m. American Airlines Flight 77 crashed into the building known as the Pentagon, located across the Potomac River from the nation's capital. At the time of impact, its speed was estimated at 530 mph.

While the Twin Towers were commercial skyscrapers — two of the tallest in the world at the time — the Pentagon is a very low building, built like a five-sided bunker. The damage may have been less dramatic to the casual viewer, but the attack on the Pentagon was more meaningful because of the building's military use. The mission of the Department of Defense is "to provide the military forces needed to deter war and to protect the security of our country." Attacking the headquarters of a nation's military is a wartime action that jolted the citizenry from its disbelief. It had been nearly an hour since the first attack in New York City — 230 miles northeast of the Pentagon.

President George W. Bush was taken to a secure location, the White House and Capitol buildings were evacuated, and thousands of aircraft across the American skies were ordered to land immediately. A third hijacked aircraft, United Flight 93, crashed into a Pennsylvania field, a mere 20 minutes by air from downtown Washington, D.C.

9:59 a.m. - The WTC South Tower Collapses

close-up of smokey skyscraper collapsing onto itself as another tower burns nearby
The South Tower Collapses September 11, 2001 in New York City. Thomas Nilsson/ Getty Images (cropped)

Back in New York City, the twin towers smoldered and burned. Some occupants jumped to their deaths. The intense heat of the jet fuel cannot melt metal, but heat and flames from each crash probably weakened the steel truss system and steel columns around the facadea. Because the second aircraft landed on lower floors, more weight had to be redistributed from the top floors. By 9:45 a.m. ET, a witness reported that the floors in the south tower were buckling. Videos confirmed the observations.

The south tower was the first to collapse, although it was the second to be attacked. At 9:59 a.m. the entire skyscraper fell upon itself within 10 seconds. Tower 1, just north of it, stood smoldering.

10:28 a.m. - The WTC North Tower Collapses

Smoke Rises Over the New York Skyline After the World Trade Center Attack -- black rail, water, skyline in distance
The Changed Skyline of Lower Manhattan. Hiro Oshima/Getty Images (cropped)

Because the jets struck the two tallest buildings in the World Trade Center complex on the upper floors, the weight of the buildings caused their own collapse. As each concrete slab floor gave way, it smashed into the floor below. The massive downward crush of floors crashing, or pancaking, on floors, sent out enormous clouds of debris and smoke.

At 10:28 a.m. ET, the north tower collapsed from the top down, pancaking into dust. Researchers estimate that the displaced rush of air — faster than the speed of sound — caused sonic booms.

Search and Rescue Through the Wreckage

A New York City fireman calls for 10 more rescue workers to make their way into the rubble of the World Trade Center September 14, 2001 days after the September 11, 2001 terrorist attack
Rescue Efforts Began Immediately. Jim Watson U.S. Navy/Getty Images (cropped)

For days after the terrorist attack, rescue workers continued to sift through the wreckage of the World Trade Center, searching for survivors.

Days Later the Skeletal Remains of the WTC

An aerial view shows twisted steel and smoke from the site of the World Trade Center terrorist attack September 15, 2001 in New York City
A Smoldering WTC, Four Days After Terrorists Attack. Gregg Brown/Getty Images (cropped)

Four days after the World Trade Center towers collapsed, white ashes covered the streets and skeletons of shattered walls. What remained bore an eerie resemblance to the original twin tower structures designed by architect Minoru Yamasaki. Some of the original tridents — the vertical, three-pronged exterior steel cladding — are displayed at the National 9/11 Memorial Museum.

Five days after the terrorist attacks, ruins of the New York World Trade Center buildings still smoldered. Lower Manhattan in New York City seemed like a war zone and became known as Ground Zero.

Flying debris and raging fire from the collapsed World Trade Center towers had an impact on nearby buildings. Seven hours after the twin towers fell, the 47-story 7 World Trade Center collapsed.

After years of investigations, the National Institute of Standards and Technology (NIST) found that the intense heat on the floor beams and girders weakened a critical support column in 7 WTC.

The Survivors' Stairway

The Ruins of Building 6 and the north tower, smokey, ash-covered metal framework in near total destruction
The Survivors' Stairway B from the North Tower. Gregg Brown/Getty Images (cropped)

Ten days later, the meaning of objects and architecture was beginning to be digested. In addition to the iconic trident-designed steel framing, a stairway survived in the collapse of the north tower. More miraculously, 16 people on stairway B survived as the north tower fell around them. The miracle of stairway B YouTube video documents the survivors' journey. The stairway, now called the Survivors' Stairway, is displayed at the National 9/11 Memorial Museum, who has also provided a PDF lesson plan to help younger students appreciate the concepts of evacuation and safety in stairways.

Buildings Destroyed in Lower Manhattan

In addition to the destruction of the twin towers and 7 WTC, many other nearby buildings did not survive the collapse, including buildings six, five, four, and three (the Marriott World Trade Center Hotel). St. Nicholas Greek Orthodox Church was also destroyed.

The Deutsche Bank Building at 130 Liberty Street (1974) was severely damaged, condemned, and then demolished.

Buildings Damaged, but Eventually Restored

The Manhattan Community College's Fiterman Hall at 30 West Broadway was severely damaged, but this City University of New York (CUNY) building was rebuilt.

The World Financial Center complex, designed by Cesar Pelli in the 1980s, was damaged but became the public's overlook on what eventually became America's most watched construction site. The 1907 building at 90 West Street designed by Cass Gilbert was restored, as was the 1927 Verizon Building, One Liberty Plaza, designed by SOM in 1973, the 1935 U.S. Post Office at 90 Church Street, and the Millenium Hilton is back in business.

What has changed? New York's skyline has changed forever.

Sources

  • National Commission on Terrorist Attacks Upon the United States. The 9/11 Commission Report. July 22, 2004.
  • National Institute of Standards and Technology. Final Report on the Collapse of the World Trade Center Towers. NIST NCSTAR 1. September 2005.