Two trains collided head-on in western Switzerland on Monday evening, killing the driver of one and injuring at least 35 passengers.
Both were regional trains travelling to and from Lausanne.
At least five of the injured had to be airlifted to a local hospital, others were treated on the spot by paramedics.
The collision happened outside the station of Granges-pres-Marnand in Vaud canton about 50 kilometres south west of the capital Bern.
In the morning light an investigation began into what caused the accident and why the two trains ended up on the same track.
A spokesperson for the Swiss rail company CFF said the two trains should have crossed at the station, thanks to a track system that allows them to pass one another.