'Safety system' derails train

Four people were killed in the Hatfield crash

Investigators believe a safety system deliberately derailed an empty train as it moved out of sidings in Hertfordshire.

The train is thought to have gone through a signal at danger, triggering the system which prevented it from going onto the East Coast main line

The incident happened just a few miles from the scene of last year's Hatfield disaster, in which four people died and dozens were injured.

Three of the train's four carriages came off the track, but stayed upright. No one was hurt.

'Trap' points

The West Anglia Great Northern train travelling at a speed of 6-10 mph on its way to Welwyn Garden City station when it derailed at 0649BST on Friday.

It is thought to have been stopped by "trap" points, which prevent trains which are leaving sidings from going into the path of passenger trains.

Railtrack said the train's route to Welwyn Garden City station would not have crossed any East Coast tracks.

Both Railtrack and the Health and Safety Executive are investigating the derailment.

The train operator WAGN said there was disruption to services into London this morning following the incident.

Four other trains were trapped in the sidings behind the derailed train, which stopped them being brought into service. A crane was due to clear the track.

The train involved had been expected to continue to travel from Welwyn Garden City to King's Cross station, in London.