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".
Eleanor J. Hill
According to U.S. State Department cable of February 2010, released by WikiLeaks in 2011, the FBI has investigated another suspect, Mohammed al-Mansoori, who had associated with three Qatari citizens who had flown from Washington to London on the eve of the attacks, after allegedly surveying the World Trade Center and the White House. U.S. law enforcement officials said that the information about the four men was "just one of many leads that were thoroughly investigated at the time and never led to terrorism charges". An official added, however, that the three Qatari citizens have never been questioned by the FBI. Eleanor Hill, the former staff director for the congressional joint inquiry on the September 11 attacks, said the cable reinforces questions about the thoroughness of the FBI's investigation. She also said that the inquiry concluded that the hijackers had a support network that helped them in different ways. The three Qatari men were booked to fly from Los Angeles to Washington on Sept. 10, 2001, on the same plane that was hijacked and piloted into the Pentagon on the following day, but did instead fly from Los Angeles to Qatar, via London. While the cable states that Mansoori would be currently under investigation, U.S. law enforcement officials said that was no active investigation of him or of the Qatari citizens mentioned in the cable.