A roller coaster car on "The Smiler" at Alton Towers Resort in Staffordshire, has collided with an empty car leaving four people with serious injuries.
According to a statement from the UK theme park, 16 people were on the ride when the accident happened but everyone was evacuated, and the four with serious injuries were transported to hospitals.
2 men, aged 18 and 27, and two women, aged 17 and 19, suffered serious leg injuries, and all four were flown to regional hospitals for treatment. 12 others however had less serious injuries.
Nick Varney, chief executive of Merlin Entertainments, which operates Alton Towers said in a statement
"This has been a terrible incident and a devastating day for everyone here. I would like to express my sincerest regret and apology to everyone who suffered injury and distress today and to their families,"
While the cause of the crash was unclear, Varney said a full investigation was underway.