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".
Hijackers in the September 11 attacks
Two flight attendants called the American Airlines reservation desk during the hijacking. Betty Ong reported that "the five hijackers had come from first-class seats: 2A, 2B, 9A, 9C and 9B." Flight attendant Amy Sweeney called a flight services manager at Logan Airport in Boston and described them as Middle Eastern. She gave the staff the seat numbers and they pulled up the ticket and credit card information of the hijackers, identifying Mohamed Atta.