When an experienced rock climber fell to her death at a Grapevine climbing gym in September, authorities called it a 'bad accident.'
But News 8 has learned that falls by experienced climbers are a well-known problem in the climbing wall industry.
The death investigation report, released by Grapevine police, shows 52-year-old Susan Mailloux of Irving failed to clip her harness to a safety line, called a belay system, at the Summit Climbing Gym in Grapevine.
In the report, witnesses told police that Mailloux 'looked like she knew what she was doing.' And even though 'she thought she was clipped in' to her rope line, in fact, 'the belay system was not attached to (her) harness.'
When she got to the top of the wall, she, 'let go and fell to the ground.'
Mailloux was using an auto-belay device. The auto-belay holds the line taut while the climber without a partner goes up the wall. It then gently lowers a climber to the ground when they let go.
So how does an experienced climber working at her own risk make such a simple life-or-death mistake?
The climbing industry is trying to answer that very same question, because it turns out experienced climbers forgetting to clip-in is ongoing problem.
'It is a well-known problem in the industry,' said Dan Hague, who is a climbing gym owner in Virginia. He helped write industry safety standards, and provides expert witness testimony for people who are injured in gym accidents.
Gague said Mailloux's death is the only climbing fatality he's heard about in his 20 years in the business, and it's a wake-up call for the industry.
'In my experience, the primary reason that people are injured using these devices is not that the device fails, but they fail to simply clip into it before they start climbing,' he said.
On a regular belay, climbers work in pairs. After checking their own equipment, Hague says, climbers should double-check each other's equipment.
'In the case of the auto-belay system, there is no double-check,' he explained.
The problem is significant enough that a climbing gear company from Minnesota called Nicros invented a device that sets off an alarm when a climber leaves the ground without clipping in. It's been on the market for less than two years, but so far, it's an expense only a few gyms are willing to pay for.
Most rely on industry safety guidelines that emphasize training and education.
'My opinion is, yes, a gym has some responsibility to make sure that you're warned and protected to some degree from yourself,' Hague said.
But sometimes, for people like Susan Mailloux, that's not enough.