The September 11 attacks, commonly known as 9/11, were four coordinated suicide terrorist attacks carried out by the militant Islamic extremist network Al-Qaeda against the United States on Tuesday, September 11, 2001. That morning, nineteen terrorists hijacked four commercial airliners scheduled to travel from the northeastern U.S. to California. The hijackers crashed the first two planes into the Twin Towers of the World Trade Center in New York City, and the third plane into the Pentagon (the headquarters of the American military) in Arlington, Virginia. The fourth plane was intended to hit a federal government building[e] in Washington, D.C., but crashed in a field following a passenger revolt. The attacks killed nearly 3,000 people and instigated the global war on terror. The first impact was that of American Airlines Flight 11 at 8:46 am, into the North Tower of the World Trade Center complex in Lower Manhattan. Seventeen minutes later, at 9:03 am, the World Trade Center's South Tower was hit by United Airlines Flight 175. Both 110-story towers collapsed within an hour and forty-two minutes, precipitating the collapse of other World Trade Center structures including 7 World Trade Center, and damaging nearby buildings. A third flight, American Airlines Flight 77, crashed into the west side of the Pentagon in Arlington County, Virginia, at 9:37 am, causing a partial collapse. The fourth and final flight, United Airlines Flight 93, flew in the direction of Washington, D.C. Alerted of the previous attacks, the plane's passengers attempted to regain control, but the hijackers ultimately crashed the plane in a field in Stonycreek Township, Pennsylvania, near Shanksville, at 10:03 am. Investigators determined that Flight 93 was targeting either the U.S. Capitol or the White House.
