By Toby Sterling
VOORSCHOTEN, Netherlands (Reuters) -A Dutch passenger train rammed into a maintenance crane that stood on the railway tracks early on Tuesday near The Hague, killing the equipment operator and injuring dozens of passengers as the train derailed.
The maintenance work was planned and standard, but "we have no idea how the crane got on the track which was still open for traffic," John Voppen, the CEO of railway infrastructure firm ProRail, told a news conference.
The front carriage of the night train from Leiden city to The Hague - one of the Netherland's busiest routes - hit the crane and derailed, ploughing into a field by the village of Voorschoten, emergency services said.
A second carriage lay on its side. The double-decker train's windows were smashed.
"There was just panic" on the train after the crash, but emergency services were quick to arrive and evacuate people, said Ingrid de Roos from the Hollands Midden emergency services.
Nineteen of those wounded were taken to hospital, while some of the others were treated on the spot or in nearby homes.
The accident happened at around 3:25 a.m. (0125 GMT).
"The crane was part of maintenance work on two tracks which were closed for traffic, while two other of the total of four tracks remained open for train traffic," said ProRail's Voppen.
"I have been working in the rail industry for years, and I don't understand how this could have happened. We are going to launch a full inquiry."
A freight train had hit the crane as well, ProRail said.
Train services will be suspended for days on the route between The Hague and Leiden due to the incident.
Dutch construction group BAM confirmed that an employee had died in the accident.
The driver of the passenger train was in hospital with bone fractures, Dutch railways NS CEO Wouter Koolmees said at the news conference.
Prime Minister Mark Rutte and the Netherlands' royal family were among those who expressed their sympathy for the victims.
"My thoughts are with the relatives and with all the victims. I wish them all the best," Rutte said in a tweet.
"We deeply sympathize with all of them," King Willem-Alexander and Queen Maxima said. Willem-Alexander later visited the site of the accident, about 10 kilometres from his residential palace.