The Amtrak train that derailed along one of the the busiest US tracks on Wednesday, killing eight and injuring more than 200, may have been struck by an object in the moments before it crashed, investigators said.
National Transportation Safety Board (NTSB) member Robert Sumwalt said an assistant conductor aboard the train told investigators she heard Amtrak engineer Brandon Bostian talking over the radio to an engineer for a regional railroad just before the crash.
The regional engineer, who was in the same area as the Amtrak train, said his train had been hit by a rock or some other projectile.
The conductor heard Mr Bostian say the same had happened to his Amtrak train, according to Mr Sumwalt.
The windscreen of the Amtrak train was shattered in the accident, but one area of glass had a breakage pattern that could be consistent with being hit by an object, he said, and the FBI is investigating.
Mr Sumwalt declined to speculate about the significance of a projectile striking the train, but the idea raised the possibility the engineer might have been distracted, panicked or even wounded in the moments before the train left the rails.
The Southeastern Pennsylvania Transportation Authority does not yet know what caused the damage to its train that night, said Jerri Williams, its spokeswoman.
SEPTA trains travelling through the area — including one of the poorest and most violent parts of Philadelphia — have had projectiles thrown at them in the past, whether by vandals or teenagers, she said.
It was unusual that the SEPTA train was forced to stop on Tuesday night.
Shattered window
Not long before the derailment, two passengers on a southbound Amtrak told The Philadelphia Inquirer that something shattered a window on their train as it passed through the same area.
They said Amtrak police boarded the train at 30th Street station in Philadelphia to document the damage.
NTSB spokesman Peter Knudson said the board was seeking more information about the other Amtrak train's window damage.
The engineer, who had been working that route for several weeks, told investigators he does not recall anything after ringing the train’s bell as he passed by the North Philadelphia station a couple of minutes before Tuesday night’s crash.
The engineer told the NTSB yesterday that he felt comfortable with the train and was not fatigued, Mr Sumwalt said.
In the minute before the derailment, the Amtrak train accelerated from 112km/h to more than 160km/h, even though the curve where it came off the tracks has a maximum speed of 80km/h.
It is not clear whether Mr Bostian manually accelerated, Mr Sumwalt said, though a data recorder shows that he did engage a braking system seconds before the derailment.
Experts say the railroad’s signalling system would have slowed the train automatically if it had hit the maximum speed allowed on the line, but older cab-signal and train-control systems do not respond to localised speed restrictions.
Preliminary checks have not found any pre-existing problems with the train, the rail line or the signals.
On Friday, the first funeral was held for one of those killed in the wreck. US Naval Academy midshipman Justin Zemser (20) was laid to rest on Long Island, New York.
PA