September 11 attacks

The September 11 attacks, commonly known as 9/11, were four coordinated Islamist suicide terrorist attacks carried out by al-Qaeda against the United States in 2001. That morning, 19 terrorists hijacked four commercial airliners scheduled to travel from the New England and Mid-Atlantic regions of the East Coast to California. The hijackers crashed the first two planes into the Twin Towers of the World Trade Center in New York City, two of the world's five tallest buildings at the time, and aimed the next two flights toward targets in or near Washington, D.C., in an attack on the nation's capital. The third team succeeded in crashing into the Pentagon, the headquarters of the U.S. Department of Defense in Arlington County, Virginia, while the fourth plane crashed in rural Pennsylvania following a passenger revolt. The attacks killed nearly 3,000 people and instigated the multi-decade global war on terror. The first impact was that of American Airlines Flight 11, which crashed into the North Tower of the World Trade Center complex in Lower Manhattan at 8:46 a.m. Sixteen minutes later, at 9:03, the World Trade Center's South Tower was hit by United Airlines Flight 175. Both 110-story skyscrapers collapsed within an hour and forty-one minutes, bringing about the destruction of the remaining five structures in the WTC complex and damaging or destroying nearby buildings. A third flight, American Airlines Flight 77, crashed into the Pentagon at 9:37 a.m., causing a partial collapse. The fourth and final flight, United Airlines Flight 93, flew in the direction of the capital. Alerted to the previous attacks, the passengers retaliated in an attempt to take control of the aircraft, forcing the hijackers to crash the plane in a Stonycreek Township field, near Indian Lake and Shanksville, at 10:03 a.m. Investigators determined that Flight 93's target was either the United States Capitol or the White House. Within hours of the attacks, the Central Intelligence Agency had determined that al-Qaeda was responsible. The United States formally responded by launching the war on terror and invading Afghanistan to depose the Taliban, which rejected the conditions of U.S. terms to expel al-Qaeda from Afghanistan and extradite its leaders. The U.S.'s invocation of Article 5 of the North Atlantic Treaty—its only usage to date—called upon allies to fight al-Qaeda. As U.S.