World Trade Center site
On the morning of September 11, 2001, Islamic terrorists affiliated with Al-Qaeda hijacked American Airlines Flight 11 and United Airlines Flight 175, both which were en route to Los Angeles, and intentionally crashed them into the two main towers of the World Trade Center. The towers collapsed within two hours of the collisions. 2,606 people, including 2,192 civilians, 71 law enforcement officers, and 343 firefighters, who were in the towers and in the surrounding area died in the attacks, as well as 147 civilians and the 10 hijackers aboard the two airliners. After the collapse of the World Trade Center, hospital workers and law enforcement officers began referring to the World Trade Center site as "Ground Zero".
Al-Qaeda
The September 11 attacks on America by al-Qaeda, killed 2,977 people, including 2,507 civilians, 343 firefighters, 72 law enforcement officers, and 55 military personnel. Two commercial airliners were deliberately flown into the twin towers of the World Trade Center, a third into the Pentagon, and a fourth, originally intended to target either the United States Capitol or the White House, crashed in a field in Stonycreek Township near Shanksville, Pennsylvania. It was also the deadliest foreign attack on American soil since the Japanese attack on Pearl Harbor on December 7, 1941.