September 11 attacks

The September 11 attacks (also referred to as September 11, September 11th, or 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 consisted of suicide attacks used to target symbolic U.S. landmarks.

Four passenger airliners—which all departed from airports on the U.S. East Coast bound for California—were hijacked by 19 al-Qaeda terrorists to be flown into buildings. 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 in the Pentagon's western side. The fourth plane, United Airlines Flight 93, initially was steered toward Washington, D.C., but crashed into a field near Shanksville, Pennsylvania, after its passengers tried to overcome the hijackers. In total, the attacks claimed the lives of 2,996 people (including the 19 hijackers) and caused at least $10 billion in property and infrastructure damage and $3 trillion in total costs. It was the deadliest incident for firefighters and law enforcement officers in the history of the United States, with 343 and 72 killed respectively.