Amsterdam - Locomotives on Sunday towed away two trains involved in a head-on collision that seriously wounded 42 people - an incident a top rail official described as one of the worst train crashes in the Netherlands' recent history.
"Two trains colliding on the same track is a nightmare," Bert Meerstadt, director of national railroad operator NS, told reporters as the vehicles were towed and technicians began studying the tracks for damage.
The Saturday evening crash in Amsterdam involved a double-decker intercity train and a commuter train.
Amsterdam Mayor Eberhard van der Laan said 42 people were seriously injured. Dozens more passengers sustained minor injuries.
Meerstadt declined to speculate on what caused the collision. He said crash investigators would study black box recorders on both trains.
The accident happened near a popular park on a busy stretch of track close to Amsterdam's Central Station where trains generally do not travel at full speed.
Two separate investigations will focus on whether human error or a mechanical fault led to the trains colliding on the same stretch of track.