Shanksville, borough (1990 pop. 235), in Somerset co., SW Pa., on the Stonycreek River, which is spanned by an 1881 covered bridge. Shanksville is situated in an agricultural area where corn, oats, and livestock are raised; there also are dairy farms and windpower facilities. During the terrorist attacks of Sept. 11, 2001, which destroyed the World Trade Center and damaged the Pentagon, a Boeing 757 aircraft crashed into a hillside near Shanksville. Heading from Newark, N.J., to San Francisco, United Airlines Flight 93, with 40 passengers and crew, had been taken over by four Al Qaeda hijackers and flown toward Washington, D.C. It was later determined that several passengers, aware of the other attacks, had sought to overpower the hijackers while they were flying over a rural area, leading the hijackers to crash the plane, killing all on board. The passengers' actions saved untold lives at the intended target, which is believed to have been the U.S. Capitol. The site of the crash is now part of the Flight 93 National Memorial, and a permanent memorial is under construction.