Much is still uncertain about the train accident in Voorschoten that left one person dead and some 30 hurt, became clear in a press conference on the incident on Tuesday morning. An NS intercity train and a freight train collided with a construction train at the site for rail works on two unused tracks, ProRail CEO John Voppen said at the press conference. How that happened is under investigation. The police also launched a criminal investigation.

The person killed was an employee of the construction company BAM, a spokesperson for the company confirmed to NRC. The construction crane involved in the collision also belonged to the company, the spokesperson confirmed but could say nothing further about the victim’s identity.

Voppen said he was “100 percent sure” that the crane was not on the tracks used by trains, but he couldn’t say how the trains then collided with it. “I’ve been working on the rail for 17 years, and I’ve never experienced anything like this,” Voppen said. “The construction crane did not stand on the tracks used by trains. How the crash could have happened, we don’t know yet.”

The police and the Dutch Safety Board are investigating what happened. The investigation will focus on how the accident occurred if the crane was supposed to be on one of two tracks taken out of service for maintenance, leaving two other tracks available for overnight passenger and freight train traffic. The investigation should also show if the crane was positioned where it was supposed to be and if the trains were on railroad track sections that were in service.

The initial investigation suggested that the freight train first struck the crane, which then went flying off the track it was on and wound up in the path of the passenger train. The NS passenger train was headed southbound from Leiden.

The police are also investigating whether any criminal offenses have been committed, a police spokesperson said at the press conference. “We cannot say anything meaningful about that at the moment,” she said.

Hans Zuidijk, the regional fire department commander and the head of the Hollands-Midden Security Region, confirmed there were 19 people hospitalized, including some who suffered severe injuries and others who suffered minor injuries, but refused to be more specific.

All of the victims had left the scene within two hours of the accident, Zuidijk said. “After that, we could prepare the location for investigation.

Everyone at the press conference expressed concerns and support for the victims and their loved ones. “I am shocked by what happened,” NS CEO Wouter Koolmees said. “Our train driver is hospitalized with broken bones. Two conductors are doing well under the circumstances. We wish the injured passengers a lot of strength.”

“Like everyone, we have a lot of questions,” Koolmees said. “We are fully cooperating with the investigations to see what happened and what caused it.”

Voppen said that the train crash would halt train traffic between Leiden and The Hague for days. The damage to the infrastructure is enormous, he said.