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".
Mohamed Atta
The hijacking began at 8:14 am — 15 minutes after the flight departed — when beverage service would be starting. At this time, the pilots stopped responding to air traffic control, and the aircraft began deviating from the planned route. At 8:18 am, flight attendants Betty Ong and Madeline Amy Sweeney began making phone calls to American Airlines to report what was happening. Ong provided information about lack of communication with the cockpit, lack of access to the cockpit, and passenger injuries. At 8:24:38 am, a voice believed to be Atta's was heard by air traffic controllers, saying: "We have some planes. Just stay quiet and you will be OK. We are returning to the airport." "Nobody move, everything will be OK. If you try to make any moves you'll endanger yourself and the airplane. Just stay quiet." "Nobody move, please. We are going back to the airport. Don't try to make any stupid moves." The plane's transponder was turned off at 8:21 am. At 8:46:35 am, Atta flew the plane into the North Tower of the World Trade Center.