The National Transportation Safety Administration has concluded that the engineer of the Amtrak train that derailed in Philadelphia was not using his cell phone at the time.

Wreckage of the Amtrak train that derailed Tuesday, May 12, 2015 in north Philadelphia, (Win McNamee/Getty Images)

In a second update issued on their investigation into the May 12th derailments, the NTSB's analysis of phone records shows engineer Brandon Bostian did not make any calls, texts or used any data at the time of the incident. "Amtrak’s records confirm that the engineer did not access the train’s Wi-Fi system while he was operating the locomotive," says the report.

According to the report, "The NTSB is conducting a detailed examination of the engineer’s cell phone calls, texts, data and cell phone tower transmission activity records from the phone carrier; and records from Amtrak’s on-board Wi-Fi system."

Bostian told investigators he doesn't remember the crash that killed 12 people and says his cell phone was stored tn his baggage. The NTSB has said Bostian, who suffered a head injury in the crash, has been cooperative but says he cannot recall the moments before the accident.

An earlier two-page preliminary report estimates damage from the crash at more than $9.2 million.

Brandon Bostian, shown here in 2007, doesn't remember the Amtrak accident that occurred Tuesday night, with him at the controls, his lawyer said Thursday. (Huy Richard Mach/St. Louis Post-Dispatch via AP)

Investigators have said previously that the train accelerated to 106 miles per hour in the last minute before entering a curve where the speed limit is 50 mph. In the last few seconds the brakes were applied with maximum force, but the train was still traveling at over 100 mph when it left the tracks.

Engineers aren't allowed to use phones while operating trains or preparing them for movement, but determining whether Bostian was using the phone was a complicated process.

The phone was used to make calls and send text messages the day of the accident, but inconsistencies in phone records presented difficulties, NTSB Chairman Chris Hart told Congress last week. The voice and text messages were recorded in different time zones and may not have been calibrated to the exact time as other equipment on the train, such as a camera focused on the tracks and a recorder that registers how fast the train was moving and actions by the engineer, he said.

Accident investigators have said previously that they have not found any mechanical problems with the train. The track had been inspected not long before the crash.

Investigators are looking at other causes of the derailment including:

  •  A mechanical or equipment failure. Investigators have examined the train braking systems, signals and track. Thus far, no anomalies have been noted, but work is ongoing.
  • Operator fatigue. Engineer Brandon Bostian's activities in the time prior to the May 12 crash which killed eight people and injured about 200 others will be documented to see if a lack of sleep might have caused him to nod off. He has told investigators he can't remember the immediate period before the crash.
  •  Distraction. Even though investigators have ruled out the most obvious uses of Bostian's cellphone, they are still examining the phone to determine if it was being used in some other way, such as use of an app, before the crash.
  •  Vandalism. There were reports of vandals throwing rocks or other objects at passing trains around the time of the derailment. The locomotive had windshield damage, and it hasn't been determined whether the damage was from a thrown object or came as a result of the derailment. The FBI found no evidence of damage that could have been caused by a firearm.

At a Senate commerce committee hearing on train safety later Wednesday, NTSB board member Bella Dinh-Zarr said that while investigators have ruled out the most obvious uses of the phone before the crash, they have not ruled out some other possible uses such as use of an app.

To determine whether the phone was in "airplane mode" or was powered off, investigators in NTSB's laboratory have been examining the phone's operating system, which contains more than 400,000 files of metadata. Investigators are also obtaining a phone identical to the engineer's phone and will be running additional tests to validate the data.

Congress mandated in 2008 that Amtrak, commuter railroads and freight railroads install positive train control by the end of this year. Amtrak still has to do extensive testing of the system but will meet the deadline, officials have said.


 The Associated Press contributed to this report