A cleaner stole an empty commuter train from a depot and drove it off the rails and into a Swedish apartment building.
Police said the woman was seriously injured in the early morning crash outside Stockholm and was flown to hospital. No one else was hurt.
Train operator Arriva said the woman, in her 20s, stole the four-car train at a depot outside the city.
She then drove it about a mile to the end station on the railway line, where it jumped off the tracks and crashed into a three-storey building.