A boy died after falling from an adventure park zip wire in Snowdonia because he hadn't been secured into his safety harness properly, an inquest heard.
Bailey Sumner, 11, fell from the newly-installed 475ft-long Swampflyer ride at the award-winning GreenWood Forest Park near Caernarfon, Gwynedd, in April 2011.
A carabiner clip, normally used by climbers, was connected to a 'false loop' in the safety attachment, an inquest jury at Dolgellau was told.
The site's managing director, Stephen Bristow, said it should have been spotted by staff during the pre-launch checks.
"The training required them to be absolutely rigorous about what they were doing," he said.
Coroner Nicola Jones told the eight jurors: "What we want to know is how he came to die.
"This isn't a court that deals with any issues of blame. Nobody is on trial here."
Pathologist Dr Anthony Caslin said Bailey, from Blackpool, died after suffering a brain injury due to a fractured skull.
The Swampflyer opened on April 17, 2011, a week before the accident. It was taken down immediately afterwards.
Mr Bristow said he didn't foresee, nor had he been warned, about the risk of a false loop.
The hearing continues and is expected to last for three days.