An elderly woman has died and five other passengers have been seriously hurt in a train derailment in Cumbria.
Part of the train is left raised in the air at a sharp angle
Several carriages were left on their side after a Virgin London to Glasgow service crashed at Grayrigg, near Kendal, at 2015 GMT, at about 95mph.
Police said 22 people went to hospital and dozens more were "walking wounded".
Investigators say no cause has yet been established, but police said their inquiry was focusing on a set of points which could be "significant".
Rail union chief Bob Crow had earlier said he had been told the accident was because of a points failure.
One of the passengers, BBC executive Caroline Thomson, said the train "did a sort of bump".
"It suddenly appeared to hit something and then lurched very, very badly from side to side in a very dramatic way."
The train had about 120 people on board, Supt Jon Rush, of Cumbria Police, told a news conference.
He said 22 passengers had been taken to three hospitals. The Royal Lancaster Infirmary and the Royal Preston Hospital took the most serious casualties. A total of five people had serious injuries.
Police are still trying to establish the identity of the passenger who was killed, but they said she was an elderly female.
The line where the crash happened could be closed for five or six days, said Supt Rush. He added that investigators were trying to establish the cause of the crash.
The leader of the Rail Maritime and Transport Union, Bob Crow, told ITV News: "All our indications are that people on the scene are saying that it was a points failure.
"And I think people can dismiss the idea that it was a cow on the track or vandalism."
The train came to rest after rolling down an embankment
All but one of the train's carriages had totally come off the tracks, a Cumbria Ambulance Service spokeswoman said.
Speaking at just after midnight she added that all nine train carriages had been cleared of passengers.
She said there were 65 people with minor injuries who were treated at the scene and a nearby farm, before being taken to the Castle Green Hotel in Kendal.
Emergency crews said they faced difficult conditions, with pouring rain, waterlogged ground and narrow country lanes around the crash site.
'Very strange sound'
The Pendolino tilting trains have been introduced by Virgin over the last three years and have a top speed of 125 mph.
Network Rail said the line speed for the area where the crash took place was about 95 mph.
Virgin Trains have suspended services between Lancaster and Lockerbie, with replacement buses operating. Trains are running as normal to and from Lockerbie, and between London and Lancaster.
A spokesman said passengers travelling between Scotland and London could use GNER East Coast trains instead.
Cumbria Police helpline: 0800 056 0146
Police family liaison centre: 0800 40 50 40
National Rail Enquiries: 08457 48 49 50
Those living close to the site described hearing the crash.
Adam Pashley, 19, said: "It was one hell of a bang but I never thought it would be a serious incident.
"About 15 minutes later I was looking out of my bedroom window and suddenly I started to see police and ambulance crews."
Donald Potter said: "My house is only about 120 yards from the track and I was sitting at my desk when I heard a very strange sound, it was completely unidentifiable, like nothing I have ever heard before, and lasted for about ten seconds."
People worried about friends or relatives on the train are asked to ring a Cumbria Police helpline on 0800 056 0146 or a British Transport Police family liaison centre on 0800 40 50 40.
Passengers wanting to travel through Cumbria, meanwhile, can ring National Rail Enquiries on 08457 48 49 50 before starting journeys.