The September 11, 2001 attacks consisted of a series of coordinated suicide terrorist attacks upon the United States, predominantly targeting civilians, carried out on Tuesday, September 11, 2001.

That morning, 19 men affiliated with al-Qaeda hijacked four commercial passenger jet airliners. Each team of hijackers included a trained pilot. Two planes crashed into the Twin Towers of the World Trade Center in New York City, one plane into each tower. Both towers collapsed within two hours. The pilot of the third team crashed a plane into the Pentagon in Arlington County, Virginia. Passengers and...