NEW YORK — The Metro-North Railroad train that hurtled off the rails on a holiday weekend morning was traveling 82 mph as it approached one of the sharpest curves in the region's rail system, federal investigators said on Monday — nearly three times the speed permitted through the turn.
The throttle was still engaged — giving the engine power — until six seconds before the locomotive, in the rear of the train, came to a stop at 7:20 a.m. Sunday after careering toward the Harlem River, officials said.
Four people died in the derailment, and more than 60 were injured. The train was about half full, with about 150 people aboard.
The National Transportation Safety Board is leading the investigation, and a board member, Earl Weener, said the train's sudden power shift came "very late in the game." The board cautioned that it remained unclear if the speed was the result of human error or faulty equipment.
But the extraordinary speed — even a relative straightaway north of the crash site has a maximum allowable speed of 70 mph — shed new light on the deadliest New York City train derailment in more than two decades and heightened the focus on the engineer at the center of the investigation.
Asked if the safety board was looking into the possibility that the engineer, William Rockefeller, fell asleep, was using his cellphone or was otherwise distracted, a spokesman for the board, Keith Holloway, said, "Part of our investigation, as in all investigations, is to look at human performance factors."
Rockefeller's cellphone was recovered as "part of our routine process," Weener said, and the results of drug and alcohol tests conducted after the crash were not yet known. Rockefeller was treated at a hospital after the accident and released.
The authorities said that the train's brakes appeared to have been operating effectively shortly before the crash.
"We are not aware of any problems or anomalies with the brakes," Weener said.
Sen. Charles Schumer, D-N.Y., noted, "The train did make nine stops before coming to this curve. So clearly the brakes were working a short time before."
He added that he was told by the safety board that the tracks in the area also seem to have been in proper condition.
The safety board's interview with Rockefeller was cut short on Monday afternoon and is to continue this week, officials said.
Anthony Bottalico, the acting director of the Association of Commuter Rail Employees, said that the interview was postponed because of "the trauma of the whole thing and the lack of sleep" for Rockefeller.
Several law enforcement officials said that detectives from the New York and Metropolitan Transportation Authority Police Departments were conducting an investigation parallel to the safety board's inquiry.
This is being done to collect evidence that could be used if prosecutors determine a crime occurred, three of the officials said. The safety board is not a law enforcement agency and its role is limited to issuing findings and making recommendations.
Prosecutors from Johnson's office were at the scene of the derailment, and two officials said the prosecutors had issued subpoenas for the engineer's blood samples, for drug and alcohol testing and for his cellphone.
Bottalico predicted that "when all is said and done here," the authorities would find there was "no criminal intent."
Weener said that six seconds before the rear locomotive came to a stop, "the throttle was reduced to idle." The brakes were fully applied one second later.
Marjorie Anders, a spokeswoman with the Metropolitan Transportation Authority, likened the throttle reduction to putting a car in neutral. "It's not the equivalent of taking your foot off the gas," she said.
A crucial question, officials said, was why the train was traveling so fast as to require an emergency maneuver. Weener said that the transportation authority had provided surveillance video from the nearby Henry Hudson Bridge, but that the footage was "of low quality" and would be sent to Washington to be enhanced at the safety board's laboratory.
Information from the Associated Press was used in this report.