A cleaning woman stole an empty commuter train in a suburb of Stockholm and crashed it into a house, injuring herself, Swedish officials say.
The four-carriage train was driven out of the depot for about a mile until it jumped the tracks, becoming wedged into a three-storey building.
Police arrested a woman, who was flown to a Stockholm hospital with serious injuries. Nobody else was hurt.
A railway official confirmed the woman in custody was an employee.
"We have only heard good things about her," Tomas Hedenius, a spokesman for train operator Arriva, was quoted as saying by AP news agency.
"We're investigating how this could happen."
Three families were inside the apartment building hit by the train but nobody was injured, the spokesman added.
"It's incredibly lucky that no-one in the house was injured," police spokesman Ulf Lindgren told TT news agency.
Christer G Wennerholm, a member of the Stockholm County Council's traffic committee, said: "It shouldn't be possible for unauthorised people to drive our trains."