September 11, 2001

September 11 attacks

Al-Qaeda hijackers attack the World Trade Center and Pentagon; Flight 93 passengers counterattack

Flight 93 left Newark more than 25 minutes late. That routine delay meant its passengers learned, from phone calls, what the hijacking was for — and at 9:57 a.m. they counterattacked.

The morning of 11 September 2001

On the morning of 11 September 2001, nineteen al-Qaeda terrorists hijacked four California-bound passenger aircraft after their departures from Boston, Washington Dulles and Newark. American Airlines Flight 11, flown by plot leader Mohamed Atta, struck the World Trade Center's North Tower at 8:46 a.m.; United 175 hit the South Tower at about 9:03; American 77 struck the Pentagon's western side at 9:37.

The fourth aircraft never reached its target — probably the U.S. Capitol or the White House, the 9/11 Commission concluded, without establishing which. Passengers and crew aboard United 93, told by callers about the other attacks, began their counterattack at 9:57. The aircraft crashed near Shanksville, Pennsylvania, at 10:03:11.

At 9:25 the FAA imposed a nationwide ground stop, and minutes later — for the first time in U.S. aviation history — ordered every airborne civilian aircraft to land at the nearest practical airport.

The towers' two different clocks

The South Tower collapsed at 9:58 a.m., about 56 minutes after impact; the North Tower stood until 10:28 — about 102 minutes. Sixteen people descending the North Tower's Stairwell B survived inside the collapse: twelve firefighters, a Port Authority police officer and three civilians.

The NIST investigation dismantled the 'burning jet fuel' explanation: the fuel largely burned off in the first minutes. What brought the towers down was the combined sequence — impact damage to columns, stripped fireproofing, impaired sprinklers, then prolonged multi-floor fires fed by building contents weakening the exposed structure.

World Trade Center 7, never hit by an aircraft, burned for almost seven hours and collapsed at 5:20 p.m. — evacuated, with no deaths.

The toll

The attacks killed 2,977 victims, excluding the 19 hijackers: 2,753 in New York, 184 at the Pentagon including Flight 77's occupants, and 40 aboard Flight 93. Among the dead were 343 New York City firefighters and 37 Port Authority police officers.

The standard count does not encompass the later deaths attributed to illnesses from exposure during rescue and cleanup — a toll that continued for decades. The invasions, NATO's collective-defense decision and the two-decade war that followed were consequences of this day, not part of it.

Sources

Researched 23 Aug 2026 10 sources 3 audit passes

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

What the sources leave uncertain

Official sources round some impact and collapse times differently. The 9/11 Commission commonly gives 9:03 for Flight 175; NIST lists 9:02. The difference is seconds, not a substantive dispute.
The Commission concluded that Flight 93 was probably aimed at either the U.S. Capitol or the White House; the exact intended building is not established.
The standard count of 2,977 excludes the 19 hijackers. It also does not encompass every later death attributed to illnesses caused by exposure during rescue and cleanup work.
The 9/11 Commission’s original fatality totals were slightly lower because identifications and official counts changed after its report.