amtrak
The National Transportation Safety Board on Tuesday released its preliminary report on last month's Amtrak derailment. Above, emergency workers look through the remains of a derailed Amtrak train in Philadelphia May 13, 2015. Reuters

Amtrak engineer Brandon Bostian had used his cell phone on the same day that the train he was controlling derailed last month in Philadelphia, though it was unclear if any of that cell phone activity took place in the moments leading up to the accident, according to a preliminary report released Tuesday by the National Transportation Safety Board.

That and other information regarding the ongoing investigation into the cause of the May 12 derailment are highlighted in the two-page report. The NTSB is in possession of the cell phone and has employed forensic experts to investigate the phone and its records to determine the role it played, if any, in the accident that left eight people dead and more than 200 passengers injured.

The report also confirmed that Amtrak train 188 was traveling at a speed of 106 mph in an area with a speed limit of 50 mph before it derailed. An estimated $9.2 million in damage to the train resulted from the accident. After examining the train's brakes, train signals as well as other factors, the NTSB had not yet found any glaring issues with the train's overall functionality. Weather apparently did not factor into the derailment, the report said.

Investigators were also looking into the possibility that “vandals” threw an object at the train’s windshield to help cause the accident. The report was released while the U.S. House Transportation and Infrastructure Committee held a hearing on Capitol Hill over the derailment. To read the entire preliminary report, click here.