Emergency responders transport an injured woman from Atlantic Terminal after a January 4, 2017 on a LIRR train. View Full Caption DNAinfo/Rachel Holliday Smith

BROOKLYN — The drivers of two commuter trains that crashed last year in Brooklyn and Hoboken, New Jersey, were found to have severe sleep apnea following the collisions that killed one passenger and injured hundreds, new documents from a federal investigation show.

Both train engineers couldn’t recall the moments just before the crashes, they told National Transportation Safety Board investigators. The NTSB on Thursday released hundreds of pages from its investigation of the Jan. 4 Long Island Rail Road crash at Atlantic Terminal in Brooklyn that injured more than 104 people and the Sept. 26, 2016 New Jersey Transit crash in Hoboken that killed one passenger.

In the reports, medical examiners for the NTSB found both engineers suffered from “severe” obstructive sleep apnea syndrome, which causes drowsiness and fatigue in waking hours due to irregular breathing that interrupts normal sleep.

In tests taken after each crash, medical examiners found the driver in the Atlantic Terminal collision, Michael Bakalo, had about 101 breathing interruptions during sleep per hour; in the Hoboken crash, driver Tom Gallagher had approximately 89 interruptions per hour of sleep. A normal sleeper typically has less than five per hour, according to an apnea guide from the Harvard Medical School.

In each crash, the engineer hit the end of the track as their trains came into a terminal. Both drivers say they don’t remember how the crashes happened.

According to an interview transcript with investigators, Gallagher recalled looking at his speedometer and noting the train was going 10 miles per hour as it pulled into the Hoboken train station.

“I blew once on my horn, and I began to ring the bell. The next thing I remember was a loud bang,” he said.

NTSB investigators asked the Bakalo his last memory of approaching the Atlantic Terminal platform when he was interviewed just a day after the crash.

“Just approaching the platform, and then unfortunately the next thing I, you know, was being lunged out of my seat and, what I know now was the, you know, impact,” he said. “At that point I didn't know what the hell was going on.”

Both men are now being treated for sleep apnea, the NTSB documents say. At the time of the incidents, neither was diagnosed for the sleep condition.

The NTSB will discuss the report’s findings at a board meeting in Washington, D.C. this winter, set for Feb. 6, 2018.