The Health and Safety Executive (HSE) is to launch an investigation into the cause of a crash between two cars on the Big Dipper rollercoaster at Blackpool Pleasure Beach, Lancashire, UK, on 11 August.

More than 30 people had to be rescued by Lancashire Fire and Rescue Service (LFRS) following the incident, which led to 21 people who were sat in the front car being hospitalised with back and neck injuries, broken bones and cuts and bruises. The incident, which took place around 7.50pm, occurred approximately 20ft (6.1m) off the ground when the first car reportedly came to a sudden halt before an empty second car ploughed into the back of it.

Mark Alderson, station manager at LFRS' South Shore Fire Station, said: "There was nobody in the second car and 11 people had been safely evacuated by site staff before we arrived. However, there were 21 people of different ages in the front car who were suffering from a range of injuries. "Our crews were able to safely escort most people off the ride by guiding them down the tracks, providing physical support and reassurance that we would get them safely down."

Alderson also revealed that two people suspected of having sustained back injuries had to be rescued by a specialist rope rescue team with neck collars and spine boards before lowering them to the ground in basket stretchers. The Big Dipper was build by Philadelphia Toboggan Coasters and first opened in 1923.