Passengers on the flight had said in cell phone calls made before the crash that a bomb appeared to be strapped to one of their captors.

Just before the plane went down, killing all 44 people on board, at least three passengers said they would try to jump the hijackers. The passengers have been hailed as heroes amid speculation that they may have prevented Flight 93 from being crashed into a Washington landmark.

The FBI has finished its investigation at the crash site and found no evidence of any explosive material or evidence that the plane broke up before it hit the ground, agent Bill Crowley said Monday.

''Nothing was found that was inconsistent with the plane going into the ground intact,'' Crowley said.

Crowley did not release any information on evidence from the aircraft's cockpit voice recorder and flight data recorder. Both black boxes were found in the days following the crash.

Crowley said investigators had recovered about 95 percent of the Boeing 757 from a field near Shanksville, some 80 miles southeast of Pittsburgh. So far, the county coroner has identified 11 victims by dental records and fingerprints.

Flight 93 had been bound from Newark, N.J., to San Francisco but made an abrupt turn near Cleveland and flew back across Pennsylvania toward Washington.