It did a very similar thing last year
From http://news.bbc.co.uk/1/hi/england/southern_counties/4822328.stm
Park closes ride after 41 trapped
The Slammer ride opened in 2005 and rotates 360 degrees
A theme park ride will remain closed until it passes stringent safety checks after it broke down stranding 41 people in freezing weather for nearly an hour.
Emergency services were called to Thorpe Park, Surrey, on Saturday when the Slammer ride came to a "controlled stop" at a 45 degree angle.
People on board were trapped until park staff could lower them to the ground.
A spokeswoman said on Sunday engineers were going over the 100ft-high ride "with a fine-toothed comb".
She said the ride was nearly full, with just seven empty seats.
"It is an incredibly sophisticated and sensitive piece of equipment," she said.
"Any minor issue will automatically result in the failsafe system shutting the ride down.
"It is perfectly safe to ride in the future. All our rides go through three hours of testing by our experienced engineering team before the park is opened each morning."
The Slammer can only be ridden by people over 1.4m (4ft 6in) - about 12 years old.
