A man was seen running from the tracks just before a fast-moving early morning passenger train slammed into a stolen van that had been abandoned on the tracks at a level crossing near Wollongong in NSW.
The impact caused the first carriage of the four-car train to catapult off the tracks and land on its side metres away from Kembla Grange station on the South Coast Line about 4am on Wednesday.
A crime scene has been established and police are trying to establish how and why the Nissan van came to be on the tracks.
The impact brought down power lines and the remaining carriages were left leaning against the station's platform.
Police said considering the carnage at the scene "it's a miracle someone wasn't killed or at least seriously injured".
The shocked driver has back injuries after being trapped in the wreckage. He was extricated by rescue workers and taken to hospital.
Police said it could have been "a whole lot worse" and rail workers had indicated the wreck of the severed train had initially made them think there would be deaths.
"When they see a train in that position, they immediately expect fatalities so I think it is very fortunate no-one was hurt," a police spokesman said.
Twelve passengers were on the train, with two also taken to hospital with minor injuries along with the guard.
The train was travelling to Sydney and wasn't scheduled to stop at the station so it "it would have been travelling at speed," the police spokesman said.
"My understanding is the injuries are not severe, which is a bit of a miracle.
"A man was seen running from the scene just prior to the collision and he is certainly a focus of investigation. We would like that person to come forward if possible.
"It doesn't appear to be a case of a simple breakdown, and the fact that someone has run from the scene prior to it indicates that it's either deliberate or some sort of misadventure driving the car in that area the tracks."
The crash happened on the same day the NSW rail network is already crippled by a strike affecting up to 70 per cent of the city's trains.
Sydney Trains and NSW TrainLink said the crash inflicted substantial damage to the overhead wiring and associated infrastructure, which is likely to have impacts on services for at least a day.
Buses are replacing trains between Albion Park and Wollongong in both directions, and a shuttle train service is operating between Albion Park and Kiama.
Commuters are advised to change trains at Wollongong or Albion Park to complete their journey.
