A National Transportation Safety Board worker walks by an FBI trailer at the crash site of United Airlines Flight 93 in Shanksville, PA,12 September 2001. The plane from Newark, NJ, bound for San Francisco, CA, is believed to have been hijacked, and crashed in a field in Shanksville. Forty-five people were on board the plane, and there were no survivors. AFP PHOTO/David MAXWELL
(Photo credit should read DAVID MAXWELL/AFP via Getty Images)