A recording released by Greek authorities in the aftermath of a head-on train collision that killed at least 57 and left dozens missing revealed a station master telling a driver of one of the train to “pass the red signal.”

It wasn’t said if that was done to back up Prime Minister Kyriakos Mitsotakis’ assertion ahead of coming elections that it wasn’t official neglect but “human error,” pointing the finger at the unnamed station master new to the job, according to NPR.

The station master already had been arrested and charged with manslaughter by negligence prior to the recording and media reports said he first denied any wrongdoing, then admitted a mistake but said automated systems weren’t working.

The man, 59, hasn’t been identified in keeping with Greek privacy laws although some media gave his name as Vassilis Samaras, whose lawyer said that new information would be coming out in his defense.

But investigators found evidence that he failed to switch the rail line before a passenger train and a freight train wound up heading toward each other on the same tracks, the reports added, said the United State’s National Public Radio.

Many of the passengers were students returning from Carnival, a festival preceding the religious season of Lent, according to the Associated Press and state broadcaster ERT said the freight train was carrying heavy cargo including steel plates.

The trains collided head-on at a combined speed of of 100 mph (161 kilometers per hour) as the passenger train was exiting a tunnel under a highway in the municipality of Tempe or it would have happened inside, a worse disaster.