United Airlines Flight 93
United Airlines Flight 93 was a domestic scheduled passenger flight that was hijacked by four al-Qaeda terrorists on the morning of Tuesday, September 11, 2001, as part of the September 11 attacks. The hijackers planned to crash the plane into a federal government building in the national capital of Washington, D.C. The mission failed when the passengers fought back, forcing the terrorists to crash the plane in Shanksville in Somerset County, Pennsylvania, preventing them from reaching al-Qaeda's intended target, but killing everyone aboard the flight.
Source: Wikipedia — United Airlines Flight 93 (CC BY-SA 4.0)