Editing September 11 attacks (section)

===The four crashes===
At 8:46 a.m., five hijackers crashed American Airlines Flight 11 into the northern façade of the World Trade Center's North Tower (1 WTC). At 9:03 a.m., another five hijackers crashed United Airlines Flight 175 into the southern façade of the South Tower (2 WTC). Five 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, southeast of Pittsburgh, at 10:03 a.m. after the passengers fought the four hijackers. Flight 93's target is believed to have been either the Capitol or the White House. Flight 93's cockpit voice recorder revealed crew and passengers tried to seize control of the plane from the hijackers after learning through phone calls that Flights 11, 77, and 175 had been crashed into buildings that morning. Once it became evident that the passengers might gain control, the hijackers rolled the plane and intentionally crashed it.

Some passengers and crew members who called from the aircraft using the cabin air phone service and mobile phones provided details: several hijackers were aboard each plane; they used mace, tear gas, or pepper spray to overcome attendants; and some people aboard had been stabbed. Reports indicated hijackers stabbed and killed pilots, flight attendants, and one or more passengers. According to the 9/11 Commission's final report, the hijackers had recently purchased multi-function hand tools and assorted Leatherman-type utility knives with locking blades, which were not forbidden to passengers at the time, but were not found among the possessions left behind by the hijackers. A flight attendant on Flight 11, a passenger on Flight 175, and passengers on Flight 93 said the hijackers had bombs, but one of the passengers said he thought the bombs were fake. The FBI found no traces of explosives at the crash sites, and the 9/11 Commission concluded that the bombs were probably fake.

Three buildings in the World Trade Center collapsed due to fire-induced structural failure. The South Tower collapsed at 9:59 a.m. after burning for 56 minutes in a fire caused by the impact of United Airlines Flight 175 and the explosion of its fuel. The North Tower collapsed at 10:28 a.m. after burning for 102 minutes. When the North Tower collapsed, debris fell on the nearby 7 World Trade Center building (7 WTC), damaging it and starting fires. These fires burned for hours, compromising the building's structural integrity, and 7 WTC collapsed at 5:21 p.m. The west side of the Pentagon sustained significant damage.

At 9:42 a.m., the Federal Aviation Administration (FAA) grounded all civilian aircraft within the continental U.S., and civilian aircraft already in flight were told to land immediately. All international civilian aircraft were either turned back or redirected to airports in Canada or Mexico, and were banned from landing on United States territory for three days. The attacks created widespread confusion among news organizations and air traffic controllers. Among the unconfirmed and often contradictory news reports aired throughout the day, one of the most prevalent said a car bomb had been detonated at the U.S. State Department's headquarters in Washington, D.C. Another jet—Delta Air Lines Flight 1989—was suspected of having been hijacked, but the aircraft responded to controllers and landed safely in Cleveland, Ohio.

In an April 2002 interview, Khalid Sheikh Mohammed and Ramzi bin al-Shibh, who are believed to have organized the attacks, said Flight 93's intended target was the United States Capitol, not the White House. During the planning stage of the attacks, Mohamed Atta, the hijacker and pilot of Flight 11, thought the White House might be too tough a target and sought an assessment from Hani Hanjour (who hijacked and piloted Flight 77). Mohammed said al-Qaeda initially planned to target nuclear installations rather than the World Trade Center and the Pentagon, but decided against it, fearing things could "get out of control". Final decisions on targets, according to Mohammed, were left in the hands of the pilots.