(NBC News) The veteran engineer at the controls of the Metro-North commuter train when it derailed over the weekend has told investigators he "zoned out" just before the crash that left four people dead.
Engineer William Rockefeller told investigators he "doesn't recall any specifics" about the moments before the train left the tracks, and that the brakes failed.
Data recorders pulled from the wreckage show the brakes were applied just five seconds before the sliding and tumbling rail cars came to a stop on the banks of the Harlem River.
Investigators have not ruled out the possibility that Rockefeller fell asleep at the controls.
According to Transit sources, after years of working the afternoon-night shift his schedule changed to early mornings just two weeks before the accident.
A union official says Rockefeller is "extremely distraught over the loss of life. He's very traumatized. He's trying to put it all together."
Copyright 2013 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.