The crash on 'The Smiler' rollercoaster at Alton Towers in the UK earlier this year was caused by "human error", according to a report carried out by the park's owners.
Five people were seriously injured in the crash.
Alton Towers' owners Merlin Entertainments say the ride will re-open next year.
Sixteen people were injured on the ride when the carriage they were in crashed intoh another that had come to a halt on the track on 2 June.
One of the people seriously injured in the crash - Leah Washington, 17, from Barnsley in South Yorkshire - had her left leg amputated above the knee.
A statement the company said: "The investigation concluded that the incident was the result of human error culminating in the manual override of the ride safety control system without the appropriate protocols being followed.
"The investigation also identified areas where protocols and the training of employees should be improved.
"There were found to be no technical or mechanical problems with the ride itself."
