According to an assistant conductor's account, the Amtrak train that derailed Tuesday, killing eight people and injuring more than 200, may have been struck by an object before it careened off the tracks.
The assistant conductor claimed she heard a radio transmission in which an engineer on a regional line said his train had been struck by a projectile. The engineer on the Amtrak train then replied that his train had been struck, too, the New York Times reported.
Robert L. Sumwalt, the safety board official who is leading the investigation, said at a news conference on Friday that investigators from the National Transportation Safety Board found "a fist-sized circular area of impact on the left side of the Amtrak train's windshield."
Sumwalt asked the F.B.I. to analyze it and to begin a full investigation into what caused the fatal crash.
Though the engineer, Brandon Bostian, was "extremely cooperative" throughout questioning, he couldn't seem to recall anything about the derailment. He said he was not "fatigued or ill" at the time of the accident, according to the New York Times.
"He was specifically asked that question, and he did not recall anything of that sort," Sumwalt said. "But then again, he reported that he does not have any recollection of anything past North Philadelphia."
The assistant conductor, however, has a slightly different version of the events that took place in her account.
Sumwalt stated that she mentioned she overheard Bostian talking to an engineer on the SEPTA regional rail line who said his train had been "hit by a rock or shot at," and Bostian confirmed his train had been struck, as well.
"Right after she recalled hearing this conversation between her engineer and the SEPTA engineer, she said she felt a rumbling, and her train leaned over and her car went over on its side," Sumwalt said.
Twelve minutes before the Amtrak train derailed, a SEPTA train had been hit by a projectile, which shattered the windshield.
Bostian has been the focal point in this incident, and investigators previously reported that the train accelerated one minute before he applied the emergency brakes.
The two other conductors on board with Bostian praised his abilities and said he is very "professional."
On May 12 - the day of the crash - Bostian only had an hour of rest due to earlier issues with a malfunctioning train that put him 30 minutes behind schedule. His rest time was most likely taken up by switching trains, filling out paperwork and doing equipment checks, according to the New York Times.
Several lawyers in New York and Pennsylvania said victims of the derailment had contacted them.
"I think it's absolutely unfair to have railway companies - who have the responsibility of ensuring the safety of so many passengers, and given the dangers inherent in traveling at the speed they do - to have their liability limited," lawyer Philip Russotti said.
The investigation of the crash is ongoing.
