The driver of a train which crashed in New York on Sunday killing four people may have nodded off at the controls. The train was travelling at 82 miles per hour on a bend with a 30 miles per hour speed limit when it derailed.

The body investigating the accident says the engineer had worked for Metro North for 15 years and has been an engineer for 10 of those years.

The National Transportation Safety Board (NTSB) says the engineer had been running this route, full time since November 17th and that this was the second day of his five day work week.

Investigators download data from the Metro North recorder at the NTSB lab in Washington 

Yesterday it was revealed that results from crew alcohol breath tests were all negative, while the results of drug tests are still pending.

Crew members, including the engineer, were also interviewed by the NTSB yesterday.

New data for each station stop along the route showed no degradation of the brakes or anomalies, and brake tests performed on the train prior to the beginning of the trip also showed no anomalies, the NTSB says.

Union official Anthony Bottalico says the operator has admitted he was fighting sleep before the crash.

While the NTSB has updated the public on its investigation.