September 11th, 2001

September 11 attacks
Part of Terrorism in the United States
Top row: The Twin Towers of the World Trade Center burning 2nd row, left to right: Collapsed section of the Pentagon; Flight 175 crashes into 2 WTC; 3rd row, left to right: A firefighter requests assistance at World Trade Center site; Ground Zero; An engine from Flight 93 is recovered Bottom row: Flight 77's collision with the Pentagon as captured by three consecutive CCTV frames
Location	New York City, New York, U.S.; Arlington County, Virginia, U.S.; Stonycreek Township near Shanksville, Pennsylvania, U.S.
Date	September 11, 2001; 15 years ago (2001-09-11) 8:46 a.m. – 10:28 a.m. (EDT)
Target	World Trade Center (AA11 and UA 175) The Pentagon (AA77) White House or U.S. Capitol (UA 93; failed)
Attack type	Aircraft hijackings Suicide attacks Mass murder Terrorism
Deaths	2,996  (2,977 victims + 19 hijackers)
Non-fatal injuries	6,000+
Perpetrators	al-Qaeda (see also responsibility and hijackers)
No. of participants	19

The September 11 attacks (also referred to as 9/11) were a series of four coordinated terrorist attacks by the Islamic terrorist group al-Qaeda on the United States on the morning of Tuesday, September 11, 2001. The attacks killed 2,996 people, injured over 6,000 others, and caused at least $10 billion in property and infrastructure damage and $3 trillion in total costs.

Four passenger airliners operated by two major U.S. passenger air carriers (United Airlines and American Airlines)—all of which departed from airports in the northeastern United States bound for California—were hijacked by 19 al-Qaeda terrorists. Two of the planes, American Airlines Flight 11 and United Airlines Flight 175, were crashed into the North and South towers, respectively, of the World Trade Center complex in New York City. Within an hour and 42 minutes, both 110-story towers collapsed, with debris and the resulting fires causing partial or complete collapse of all other buildings in the World Trade Center complex, including the 47-story 7 World Trade Center tower, as well as significant damage to ten other large surrounding structures. A third plane, American Airlines Flight 77, was crashed into the Pentagon (the headquarters of the United States Department of Defense) in Arlington County, Virginia, leading to a partial collapse of the building's western side. The fourth plane, United Airlines Flight 93, initially was steered toward Washington, D.C., but crashed into a field in Stonycreek Township near Shanksville, Pennsylvania, after its passengers tried to overcome the hijackers. It was the deadliest incident for firefighters and law enforcement officers in the history of the United States, with 343 and 72 killed respectively.