(Associated Press) - The Amtrak train that derailed in Philadelphia accelerated rapidly in the final full minute before it headed into a sharp curve and crashed.

That's according to the lead investigator for the National Transportation Safety Board. Robert Sumwalt says a camera mounted on the front of the train shows it was going 70 mph 65 seconds before the video went dark. By 16 seconds before the crash, the train had increased to 100 mph, soon reaching 106 mph right before entering a 50 mph section.

Sumwalt says it's unclear if the increase in speed was the result of a manual action by the engineer. Sumwalt says engineer Brandon Bostian has agreed to speak to NTSB investigators in the next few days

Records show no anomalies with the track, signals or train itself. It had left Philadelphia's 30th Street Station on time.

The death toll reached eight today with the discovery of a body in the wreckage.