Source: Train Engineer 'Zoned Out' Seconds Before Derailment

The Metro-North train involved in Sunday’s horrific disaster derailed on a 30-mph curve because it was traveling at 82 mph, authorities revealed Monday.

Engineer William Rockefeller told investigators that he had zoned out as the train was barreling toward the bend — and that he was jolted back to reality only after a whistle went off warning him he was going dangerously fast, sources told The Post.

“He was just somehow inattentive,’’ and as soon as he realized what was happening, he jammed on the brakes, one source said.

But it was too late.

According to data from the train’s two “black box” recording devices, Rockefeller didn’t apply the brakes until just five seconds before the derailment.

The train’s throttle, or gas lever, was first thrown into the “idle” position, similar to putting a car in neutral, a source said.

Modal Trigger

Engineer William Rockefeller told investigators that he had zoned out as the train was barreling toward the bend, sources said.Photo: Reuters/Eric Thayer

A second later, the brakes were slammed. But it wasn’t enough to the seven cars and push locomotive from jumping the tracks and rolling toward the Harlem River.

The holiday-weekend wreck left four dead and 63 injured just north of the Hudson Line’s Spuyten Duyvil station in The Bronx.

Rockefeller immediately admitted zoning out to investigators at the scene Sunday, a law-enforcement source said.

He also suggested the train’s brakes had “failed to engage.’’

Investigators asked him, “Were you drinking?’’ a source said.

The 46-year-old married engineer didn’t smell of alcohol and adamantly denied he had been boozing, the source said.

The National Transportation Safety Board, which is heading the investigation, is awaiting a toxicology report.

Authorities confiscated Rockefeller’s cellphone to see if he had been texting or talking on it.

The NYPD and Bronx District Attorney’s Office have launched their own joint criminal probe and will also look at texting and drugs and/or alcohol as possible factors, sources said. They’ve subpoenaed his phone records.

While Rockefeller chatted with law-enforcement Sunday, he was less talkative Monday, the source said.

“They found him elusive and traumatized,” the source said.

NTSB member Earl Weener noted Monday that the train was speeding even before the curve, traveling 12 mph faster than the maximum limit of 70 mph in the straightaway along the Hudson River.

“At this point, we are not aware of any problems or anomalies with the brakes,’’ he added.