Most auto-belay accidents are the result of individuals failing to completely clip into the device, or forgetting to clip in entirely. ... In January 2014, Mark Hesse, 63, a climber with decades of experience, fell to his death after failing to clip into the auto-belay device in the Boulder Rock Club, Boulder, Colorado.

Can auto belay fail?

Auto belay systems do fail, but so do humans. I managed a HUGE gym in texas. After moving to CO one of the auto belays failed and a guy broke his back.

How reliable are auto belays?

This device physically blocks the start of the climbing routes, demanding interaction before one starts climbing. Aside from user error, the auto belays used in most climbing facilities today are exceedingly safe.