September 11 attacks: Quick Facts

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Nov. 7, 2026

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The September 11 attacks were coordinated suicide missions carried out against the United States in 2001 by the Islamic extremist group al-Qaeda. It was the deadliest terrorist attack on American soil in U.S. history. The 19 attackers—most of whom were from Saudi Arabia—boarded four domestic airliners on the morning of September 11, 2001, and hijacked the planes shortly after takeoff. The terrorists crashed two airplanes into the World Trade Center in New York City: American Airlines flight 11 hit the north tower, and United Airlines flight 175 struck the south tower minutes later. Both buildings soon collapsed. American Airlines flight 77 was flown into the Pentagon near Washington, D.C., and soon afterward United Airlines flight 93 crashed into a field outside Shanksville, Pennsylvania, after its passengers tried to overpower the hijackers. According to the official death toll, 2,753 people were killed in New York, 184 at the Pentagon, and 40 in Pennsylvania. All 19 terrorists died.

Facts

Also Known As	9/11 attacks
Date	September 11, 2001
Location	New York • New York City • Pennsylvania • United States • Washington, D.C.
Participants	United States • al-Qaeda
Context	USA PATRIOT Act • war on terrorism • Afghanistan War • Homeland Security Act

Top Questions

How many planes were hijacked on 9/11?

Four planes were hijacked during the September 11, 2001, attacks, three of which were used to strike significant U.S. landmarks. American Airlines flight 11 and United Airlines flight 175 were flown into the World Trade Center’s north and south towers, respectively, and American Airlines flight 77 hit the Pentagon. United Airlines flight 93 crashed in a field near Shanksville, Pennsylvania. The plane was believed to be headed to the U.S. Capitol in Washington, D.C.

How many people were killed in the September 11 attacks?

The exact number of victims of the terrorist attacks on September 11, 2001, is not definitively known due to the uncertainty about the number of people killed at the World Trade Center. The official death toll of the attacks is 2,977 people, not including the 19 terrorists. At the World Trade Center in New York City, 2,753 people died, and the remains of some victims have never been identified. The death toll at the Pentagon in Arlington, Virginia, was 184, and 40 people died near Shanksville, Pennsylvania.

Who planned the 9/11 attacks?

Al-Qaeda leader Osama bin Laden was the mastermind of the attacks, though Khalid Sheikh Mohammed was the operational planner. Mohammed Atta was selected to head the operation. He and 18 other terrorists died in the attacks.

Who was president at the time of the September 11 attacks?

George W. Bush was president of the United States on September 11, 2001. At the time of the attacks, he had been in office for roughly eight months.

Did You Know?

Up to 500,000 people were evacuated from lower Manhattan by boat. It was the largest waterborne evacuation since Dunkirk during World War II, when some 338,000 Allied troops were rescued.
One World Trade Center, the centerpiece of reconstruction at Ground Zero, opened in 2014. It is 1,776 feet (541 meters) tall, a reference to the year in which the Declaration of Independence was approved by the U.S. Continental Congress.
There were 4,546 civil aircraft flying in U.S. airspace when the FAA ordered them to land. It took about 2.5 hours to clear the airspace. Flights did not resume until September 13, 2001.