2001 · New York City, United States
The September 11 attacks were a series of coordinated terrorist attacks by the Islamic terrorist group al-Qaeda against the United States. Four passenger airliners were hijacked by 19 al-Qaeda terrorists. Two planes were flown into the Twin Towers of the World Trade Center in New York City, causing their collapse. A third plane hit the Pentagon in Arlington, Virginia, and a fourth plane, United Airlines Flight 93, crashed into a field in Pennsylvania after passengers attempted to overcome the hijackers.