Speculation that speed was a factor in yesterday's Metro North train derailment seems to have been confirmed: The NTSB says the train was going 82 MPH when it entered a 30 MPH zone.

Four died as a result of the derailment, with a further 48 injured. More as we know it.

UPDATE: Earl Weener of the NTSB said the following to the AP:

Weener said the throttle went to idle six seconds before the derailed train came to a complete stop ‚ÄĒ "very late in the game" for a train going that fast" ‚ÄĒ and the brakes were fully engaged five seconds before the train stopped.

He said investigators were also examining the engineer's cellphone ‚ÄĒ apparently to determine whether he was operating the train while distracted.

Asked whether the tragedy was the result of human error or faulty brakes, Weener said: "The answer is, at this point in time, we can't tell."