A rail union official says a commuter train engineer caught himself nodding at the controls before the train started to veer off its tracks and derailed in New York City, killing four people.
Union leader Anthony Bottalico said Tuesday that William Rockefeller "caught himself, but he caught himself too late."
Bottalico says Rockefeller told him he "nodded," akin to a momentary lapse while driving a car.
The National Transportation Safety Board is interviewing Rockefeller. Member Earl Weener says it's too soon to say whether the engineer was fully conscious around the time of Sunday's wreck in the Bronx.
He says it's too soon to say whether the wreck was the result of human error or a mechanical problem.
A lawyer for Rockefeller hasn't returned calls. A former boss calls Rockefeller a stellar employee.