Part of an automated conveyor track had become unaligned and four employees were troubleshooting the problem. One of them climbed onto the conveyor belt (about 2 1/2 feet above ground level) and braced himself on a guard cable (about 2 feet above the conveyor, aligned with the side of the belt) while sitting on another guard cable (about 1 foot above the conveyor belt). Both cables failed while the employee was trying to manipulate the conveyor with his legs/feet. He fell to the floor, striking his head and suffering two skull fractures and a brain bleed.