The accident occurred on the afternoon of Tuesday 30 May 1972 on John Collins Big Dipper roller coaster at the funfair in Battersea Park, London, which had opened in 1951 as part of the Festival of Britain.

The court heard that, after a fire had damaged the ride in 1970, second-hand stock, more than fifty years old, had been bought to replace it.

The structure, including the pedestrian emergency walkway, was in a rotted and unsafe condition, so that one victim who survived the initial impact fell through the handrail to her death.

A lengthy hearing at the Old Bailey included testimony that the Big Dipper had had mechanical problems during the weeks preceding the disaster, including another instance of a train running backwards and not being stopped by the brake, that managers were often drunk and teenaged staff used drugs, and that the brakeman on the accident run had been told to leave and had never been questioned by the police.

[9][10] In 1975 Arun Thakur, a crash victim, successfully sued the son of the owner in the High Court and was awarded £5,500 in damages.

[7] The Big Dipper was replaced with a modern steel roller coaster known as The Cyclone, but the funfair's popularity remained low.