Thirty people were hurt when two rollercoaster carriages collided on Blackpool's famous Big Dipper ride.
The second carriage hit the back of the first, which had become jammed. The cars came to rest six metres above the ground, leaving people stuck inside.
Firefighters used a specialist rope team to get people onto stretchers and down from the ride. As many as 21 people were then taken to hospital.
The ride is now shut while an investigation takes place.
The Big Dipper is one of Blackpool's most famous tourist attractions and was built in 1921.
But Ian Bell, from Coaster Force, a group dedicated to rollercoasters at theme parks, thinks that shouldn't have been a problem.
He said: "It may be an old ride, but that does not mean it is not safe. The older (they are) the more checks they have."