The Investigation

Minutes after the crash, first responders and the Pennsylvania State Police arrived on the scene as the September 11 attacks generated the largest investigation in FBI history. The investigation's primary goal was to recover enough evidence to learn who committed the crime, how it was carried out, who financed the operation, and what might happen next. Investigators quickly realized that of the four crash sites, the Shanksville location would likely yield the most evidence in the least amount of time because Flight 93 crashed in an open field, where parts of the plane, including the black boxes, personal effects, and human remains, could be recovered more easily. Enough remains were recovered to positively identify everyone on board the plane. Evidence recovered included knives, passports belonging to the terrorists, and handwritten documents in Arabic describing the terrorists' plans for the attack. Excavation of the crater reached a depth of 40 feet, where aircraft debris was no longer found. On September 24, 2001, the FBI closed its field investigation, and the Somerset County Coroner later filled the crater and restored the scene to its condition before September 11.

Pennsylvania · United States