National September 11 Memorial &amp; Museum
The National September 11 Memorial & Museum (also known as the 9/11 Memorial & Museum) is a memorial and museum in New York City commemorating the September 11, 2001 attacks, which killed 2,977 people, and the 1993 World Trade Center bombing, which killed six. The memorial is located at the World Trade Center site, the former location of the Twin Towers that were destroyed during the September 11 attacks. It is operated by a non-profit institution whose mission is to raise funds for, program, and operate the memorial and museum at the World Trade Center site.
September 11 attacks
At 8:46 am, five hijackers crashed American Airlines Flight 11 into the northern façade of the World Trade Center's North Tower (1 WTC). At 9:03 am, another five hijackers crashed United Airlines Flight 175 into the southern façade of the South Tower (2 WTC). Five hijackers flew American Airlines Flight 77 into the Pentagon at 9:37 am. A fourth flight, United Airlines Flight 93, crashed near Shanksville, Pennsylvania, southeast of Pittsburgh, at 10:03 a.m. after the passengers fought the four hijackers. Flight 93's target is believed to have been either the Capitol or the White House. Flight 93's cockpit voice recorder revealed crew and passengers tried to seize control of the plane from the hijackers after learning through phone calls that Flights 11, 77, and 175 had been crashed into buildings that morning. Once it became evident that the passengers might gain control, the hijackers rolled the plane and intentionally crashed it. 
Some passengers and crew members who called from the aircraft using the cabin airphone service and mobile phones provided details: several hijackers were aboard each plane; they used mace, tear gas, or pepper spray to overcome attendants; and some people aboard had been stabbed. Reports indicated hijackers stabbed and killed pilots, flight attendants, and one or more passengers. According to the 9/11 Commission's final report, the hijackers had recently purchased multi-function hand tools and assorted Leatherman-type utility knives with locking blades, which were not forbidden to passengers at the time, but were not found among the possessions left behind by the hijackers. A flight attendant on Flight 11, a passenger on Flight 175, and passengers on Flight 93 said the hijackers had bombs, but one of the passengers said he thought the bombs were fake. The FBI found no traces of explosives at the crash sites, and the 9/11 Commission concluded that the bombs were probably fake.