September 11 terrorist attacks: ill-fated flight path series of airline hijackings and suicide attacks committed by 19 militants associated with the Islamic extremist group al-Qaeda against targets in the United States, the deadliest terrorist attacks on American soil in U.S. history. The attacks against New York City and Washington, D.C., caused extensive death and destruction and triggered an enormous U.S. effort to combat terrorism. Some 2,750 people were killed in New York, 184 at the Pentagon, and 40 in Pennsylvania (where one of the hijacked planes crashed); all 19 terrorists died. Police and fire departments in New York were especial hard-hit: hundreds had rushed to the scene of the attacks, and more than 400 police officers. http://www.britannica.com/event/September-11-attacks



