Footage shows the scene in Tempi, central Greece, where 36 people have died, though that number likely will rise. 350 people were traveling on the train.
Early reports show a passenger and freight train were traveling on the same track.
Greek news media reported that the station manager — now arrested — had directed the freight train onto the same track as the passenger train, but the authorities declined to confirm or deny those reports.
Two of the carriages “basically don’t exist anymore,” a regional governor said, and the transport minister announced his resignation.
Rescue efforts are ongoing.