Today marks 21 years since the Potters Bar rail crash in which seven people were killed and many others injured.

On May 10, 2002, a northbound train to Norfolk derailed at high speed, killing seven and injuring 76.

As a result, part of the train wedged between the station platforms and building structures.

The incident shook the town, and the events leading up to the tragedy were subject to intense scrutiny during the years that followed.

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Welwyn Hatfield Times: A crash investigator walks by the scene of the rail crash at Potters Bar station, Hertfordshire, in 2002.A crash investigator walks by the scene of the rail crash at Potters Bar station, Hertfordshire, in 2002. (Image: PA Archive/PA Images)

RMT General Secretary Mick Lynch said: "Today we remember the victims of the Potters Bar tragedy 21 years ago.

"Potters Bar could have been avoided if safety had been put ahead of profits. 

"Those responsible for creating that lethal culture escaped prosecution for their role creating an avoidable disaster.”

In 2003, the Health and Safety Executive released a report which found that the points were poorly maintained and that this was the primary cause of the accident. 

Welwyn Hatfield Times: Hertfordshire Constabulary attended an Act of Remembrance at the memorial garden close to Potters Bar railway station to mark the 20th anniversary of the rail crash.Hertfordshire Constabulary attended an Act of Remembrance at the memorial garden close to Potters Bar railway station to mark the 20th anniversary of the rail crash. (Image: Hertfordshire Constabulary)

On May 1, 2002, the points had been inspected by a team working for Jarvis plc, a private railway maintenance company, and no issues were reported.

The year after, Network Rail brought their maintenance in house, announcing that all track maintenance would be done by its own workers instead of using private contractors.

On May 13, 2011, Network Rail was fined £3 million for safety failings related to the crash.