Yonkers - The engineer in a commuter-train derailment that killed four people over the weekend caught himself nodding at the controls just before the wreck, a union official said on Tuesday.
William Rockefeller "caught himself, but he caught himself too late," said Anthony Bottalico, leader of the rail employees union, relating what he said Rockefeller told him.
During an afternoon news conference, federal investigators said they were still talking to Rockefeller, and they would not comment on his level of alertness around the time of the Sunday morning wreck in the Bronx.
Rockefeller's lawyer did not immediately return calls.
Questions about Rockefeller's role mounted rapidly after investigators disclosed on Monday that the metro-north railroad train jumped the tracks after going into a curve at 132km/h, or nearly three times the speed limit. In addition to the four people killed, dozens were injured.
National transportation safety board member Earl Weener said on Tuesday that it was too soon to say whether the accident was the result of human error or a mechanical problem.
But he said investigators have found no evidence so far of any problems with the brakes or signals.
Alcohol tests on the train's crew members were negative, and investigators were still awaiting the results of drug tests, the NTSB official said.
On the day of the crash, Rockefeller was on the second day of five-day work week, reporting for duty at 05:04 after a typical, nine-hour shift the day before, according to Weener.
"There's every indication that he would have had time to get full restorative sleep," Weener said.
But Botallico said Rockefeller had switched just weeks earlier from the night shift to the day shift, "so he did have a change in his hours and his circadian rhythms with regard to sleep."
The New York police department is conducting its own investigation, with help from the Bronx district attorney's office, in the event the derailment becomes a criminal case.
Rockefeller himself, meanwhile, stayed out of sight. But his union and former co-workers spoke up in his defence.
"This is a man who is totally distraught by the loss of life, and he's having a tough time dealing with that," Bottalico said.
Faulted for speed
He added: "Once the NTSB is done with their investigation and Billy is finished with his interview, it will be quite evident that there was no criminal intent with the operation of his train."
With the NTSB yet to establish the cause of the crash, Governor Andrew Cuomo said on Tuesday the engineer could be faulted for the train's speed alone.
"Certainly, we want to make sure that that operator is disciplined in an appropriate way. There's such a gross deviation from the norm," he said.
Rockefeller, 46 and married with no children, has worked for the railroad for 15 years and has been an engineer for 10, according to Weener.
Rockefeller's work routine had recently changed. He had begun running that route on 17 November, two weeks before the wreck, said Marjorie Anders, a spokesperson for metro-north's parent, the metropolitan transportation authority.