A PASSENGER train that derailed near Grange was travelling at 56 mph when it came off the tracks, investigators have said.

The Rail Accident Investigation Branch has launched a government investigation into what led to the train derailing.

The Northern-operated train service, travelling between Preston and Barrow, came off the tracks at around 6:15 am on March 22.

The RAIB said the incident occurred after a section of unsupported track ‘gave way’ due to a cavity opening in the embankment on which the railway sits as the train passed through.

The Westmorland Gazette: The rear of the train following the derailment.The rear of the train following the derailment. (Image: RAIB)

One passenger onboard the train described the opening as a ‘sinkhole’.

READ MORE HERE: Passengers 'very lucky' after sinkhole derails train in Cumbria

As a result, the front three carriages of the six-carriage train became derailed and the train struck a wall situated at the top of the embankment, said the RAIB.

It remained upright and came to a standstill with the rear of the train around 31 metres beyond the cavity.

At the time of the accident, there were four staff and four passengers onboard. There were no injuries sustained, although significant damage was caused to the train and to railway infrastructure.

The line is not expected to reopen before April 8.

The investigation will seek to identify the ‘sequence of events’ that led to the accident.

It will also consider the condition of the railway and nearby drainage; the planning management of relevant railway maintenance activities; how the railway infrastructure at this location was managed in response to local flood risks, and any underlying management factors.

This will be independent of any investigation by the railway industry or its regulator, the Office of Rail and Road.

RAIB said it would publish its findings, including any recommendations to improve safety, once the investigation has concluded.

Buses are replacing trains in the meantime.