• NTSB investigation yields little evidence of mechanical glitch
  • Agency to determine formal probable cause later this year

The National Transportation Safety Board is focused on why an Amtrak train that derailed in Philadelphia last year sped to 106 miles per hour entering a sharp curve, according to about 2,000 pages of documents released Monday.

While not pinpointing a cause, the documents rule out a number of potential contributing factors. Investigators have found no evidence of failures involved with the track, the locomotive and the signals that direct the engineer that could have caused the accident, a safety board official briefing reporters said on Monday. The train’s engineer has told investigators he can’t recall the moments immediately before the crash.

Last year’s train wreck, the deadliest Amtrak accident since 1999, cast a spotlight on the railroad’s safety. Eight of the train’s 238 passengers died, and more than 200 others were injured. Federal regulators ordered the U.S. passenger rail service to immediately improve safety on its Northeast Corridor route between Washington and Boston.

The safety board will conclude the cause of the accident by this spring, according to the NTSB official.

The NTSB has looked into the possibility that an object striking the locomotive distracted the engineer, Brandon Bostian, who was operating the northbound train from Washington when the accident occurred May 12. A grapefruit-sized fracture pattern was discovered in the windshield of the locomotive after the crash. The FBI didn’t find evidence that gunfire caused the damage.

Acela Struck

An object struck an Acela train in Philadelphia near the scene of the crash Sunday night, shattering a window on a passenger car, according to Associated Press. Amtrak officials say they haven’t concluded what object hit the train.

Bostian, who suffered a head injury, has told investigators he doesn’t recall what happened prior to the crash.

In June, the NTSB determined that Bostian wasn’t using his mobile phone prior to the crash. The engineer didn’t violate Amtrak’s policy prohibiting distractions from personal electronics, the safety board said.

Bostian gave investigators his phone’s password, which allowed them to access data on the device without having to seek a subpoena, according to the NTSB. Investigators examined the phone’s operating system, which contains more than 400,000 files, according to the NTSB.

Sharp Curves

The NTSB also examined the design of the rail bed outside Philadelphia, which involves a series of sharp curves as trains make their way out of the city’s rail station going North. Investigators determined that the train accelerated to 106 mph shortly before derailing on a curved section of track with a 50 mile-per-hour speed limit.

The accident closed part of the busiest U.S. passenger-rail route for days, and Amtrak estimated it lost more than $9.2 million.

Amtrak installed more advanced automatic-braking technology known as positive train control, more widely throughout the Northeast Corridor. The NTSB has said such as system would have prevented the accident.

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