The train derailment that took four lives and injured more than 60 people over the holiday weekend may have been the result of the engineer falling asleep at the controls, authorities say.

William Rockefeller says he “zoned out” and was jerked to attention when a whistle went off, alerting him that the train was going much too fast. The Metro-North train was at around 82 mph when it came to a 30 mph-curve; according to the black box recovered from the wreckage, Rockefeller didn’t apply the brakes until just five seconds before the crash.

“He was just somehow inattentive, and as soon as he realized what was happening, he jammed on the brakes,” one source said.

The train jumped the tracks, throwing several passengers from the cars. Incredibly, because there were so many injured, authorities said they were forced to ask everyone to assist those who were more badly wounded. The traumatized passengers stepped up to the task.

Rockefeller has reportedly been cooperative with authorities and drugs and alcohol are not thought to be a factor. His cell phone has been confiscated, however, so that police can check the records to see if he might have been texting or otherwise engaged while on duty.

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