On September 11, 2001, at 10:30 am, United Airlines Flight 93 crashed in a field, killing all 40 passengers and crew members and the four terrorists who had hijacked the aircraft. The plane came over a hill approximately 40-50 feet off the ground at a speed of 563 miles per hour, and when it struck, the 7,000 gallons of jet fuel on board exploded in a ball of fire higher than the trees. Because of the quick and determined actions of the passengers and crew, the flight failed to reach the terrorists’ intended target and crashed less than 20 minutes flying time from the U.S. Capitol building in Washington, D.C. When first responders and local citizens arrived, the site and adjacent trees were still smoldering, the ground was littered with fragments of the plane, and the crash had created a crater 15 feet deep and roughly 30 feet across. During the recovery and investigation, the crater was excavated to a depth of 40 feet to recover human remains, personal effects, parts of the aircraft, and evidence. On September 24, 2001, the FBI closed its field investigation and turned the site over to the Somerset County Coroner, who intended to restore it to its condition before September 11. The crater was backfilled, covered with topsoil, and planted with grasses and wildflowers. The crash site area became the final resting place of the passengers and crew and the heart of the memorial, which would remain untouched, while the names of the 40 passengers and crew were to be placed on the wall of the Memorial Plaza as it followed the flight of the plane.