The Smiler rollercoaster at Alton Towers has broken down mid-ride - 14 months after it crashed leaving five people seriously injured.
Several people were stuck on the ride after reports a "piece of debris" had fallen from the carriage at about noon today.
"There was an evacuation and all guests are now clear," a spokeswoman for the Staffordshire theme park said.
The ride reopened in March, nine months after the horror crash which left Barnsley man Joe Pugh seriously injured.
Vicky Balch, who along with another passenger, Leah Washington, from Lancashire, had to have a leg amputated, Daniel Thorpe, from Buxton, Derbyshire, and Chandaben Chauhan, from Wednesbury, West Midlands, were also seriously injured.
In a statement, the theme park said: "Alton Towers Resort stopped The Smiler to investigate claims a piece of debris had fallen from a carriage.
"At no time were guests on the ride at any risk and all were safely removed from the ride promptly by staff, in line with our comprehensive standard procedures.
"As the health and safety of our guests is our priority, the ride will remain closed whilst the Resort's technical team investigate the matter."
In total 16 people were hurt in the incident in June 2015 which park owner Merlin Entertainments said was due to human error.