Footage emerges of deadly train crash in Spain

This is the terrifying moment the train came off the rails near Santiago de Compostela, in Spain's worst train crash for 40 years.

Security camera footage shows the train speeding around a left curve in the track, before a carriage careers off the track.

[Spain rail crash: Train was 'travelling too fast']

The tragedy has so far claimed the lives of 78 people and injured 141 more, including one Briton.

The subsequent derailment left a scene of devastation, with toppled and smashed carriages lying alongside the track.

Witnesses told how carriages piled into each other during the derailment.

It has been reported in Spain that the train was traveling 'too fast' moments before the crash.

Spanish paper El Mundo reported that the train had been travelling at nearly 140mph (220kph) in an urban zone with a speed limit of  just 50mph (80kph).

Lidia Cannon, who previously lived in the city and was visiting for the local fiesta celebrating St James, told the BBC Radio 4 Today programme: "We heard a big bang, like, we thought it was an air crash, I thought it was a car crash, other people thought it was a bomb. It was very, very loud, the noise."

Ms Cannon said people went to help and told of one man's experience of visiting the crash site.

[Spain's Rajoy declares three days of official mourning after train crash]

She said: "He couldn't cope with it. He said he was there 20 minutes but he took out a man that was asking for his wife and his wife was inside, dead. A boy was looking for his girlfriend and she was inside the train, dead.

"He was taking out people that had mobile phones in their pockets ringing all the time. He couldn't cope with it because policemen and doctors and everyone was crying and he had to leave.'

[Timeline: Worst train crashes and accident in Europe]

Alberto Nunez Feijoo, president of the region of Galicia, described the scene as "Dante-esque".

One of the passengers, Sergio Prego, said: "The train travelled very fast and derailed and turned over on the bend in the track. It's a disaster. I've been very lucky because I'm one of the few to be able to walk out."

With the dead being taken to a makeshift morgue set up in a Santiago indoor sports arena, Spanish Prime Minister Mariano Rajoy, who was born in the city, visited the crash scene.

David Cameron wrote to Mr Rajoy today, saying: 'People in Britain have been greatly saddened by this tragedy. Please pass my deep condolences to those who have lost loved ones and my thoughts and prayers to all those who have been injured.'