Instead of stopping, the train on the 235ft high ride - 'The Big One' at Blackpool's Pleasure Beach - only slowed down and was travelling at 35mph when it crashed into the back of another train, injuring 26 people. Two were still in hospital last night.
Geoffrey Thompson, managing director of the Pleasure Beach, said the exact cause of the failure would not be known until computer experts from the ride's makers, Arrow Dynamics, arrive from the United States this weekend.
Thursday's accident occurred about two hours after the ride had been shut down for an hour, apparently because of a similar computer fault. Twenty passengers were stranded for 15 minutes on a stretch of track 200ft high. Trains on the roller-coaster ride, which cost pounds 12m to build, reach speeds of 85mph. The attraction was officially opened last week.