A rollercoaster engineer has described how he thought he "messed up" before a collision between two cars that left student Gemma Savage fatally injured.
Gemma Savage was studying biomedical sciences in Durham
Eric Butters was lowering cars on the ride at Lightwater Valley when the accident happened in June 2001.
He told Skipton Magistrates' Court he had received just an hour's training on the ride and had not seen a manual.
Staff received extensive training after the death of the Durham student, he added. The inquest continues.
The inquest has already heard that Miss Savage, 20, of Wath upon Dearne, South Yorkshire, was in the front of the two cars that collided at the bottom of a dip on the Treetop Twister ride.
Mr Butters told the jury he was called to the ride after its computer system halted all the cars.
He said he was taking them down one by one by releasing a series of brakes on the rollercoaster when the accident happened.
Mr Butters said he told a colleague straight after the accident something along the lines of: "I think I messed it up."
The inquest has already heard that the manual control should only have worked after the ride's emergency stop button was pressed to disable the computer.
But faulty wiring meant that Mr Butters was able to manually operate the brakes at the same time as the computer without hitting the button.
He told Deputy North Yorkshire Coroner John Sleighthome that he had never been told to hit the emergency stop button before operating the manual controls.
Mr Butters had seen a car stuck on the steep slope before the accident "but did not think it was in the way", he added.
Miss Savage's family were present during the evidence at the inquest, which is now in its third week.