On the morning of September 11, 2001, 19 terrorists hijacked four commercial aircraft and crashed two of them into the North and South Towers of the World Trade Center complex in New York City. A third plane crashed into the Pentagon in Arlington, Virginia. After learning about the other attacks, passengers on the fourth hijacked plane, Flight 93, fought back, and the plane was crashed into an empty field in western Pennsylvania about 20 minutes by air from Washington, D.C. The Twin Towers ultimately collapsed, due to the damage from the impacts and subsequent fires. Nearly 3,000 people were killed from 93 different countries. It was the worst attack on American soil since the Japanese attacked Pearl Harbor in 1941. A detailed account of these events--plus the history that led up to them, and America's response--can be found in 9/11: The Attacks on the World Trade Center and the Pentagon.