Abstract: Two employees were delivering roofing shingles to a residence. Upon arrival at the house, the employees backed their truck, a GMC flatbed C8500 with a Clearfield conveyor system, into the driveway and extended the conveyor boom. A tree in the front yard kept the employees from swinging the boom to the roof, so one of them moved the truck forward while the other employee acted as a signaler. The signaler, who was standing to the side of the bed of the truck on the driver's side, gave the signal to stop, and the driver did so. Because the truck was loaded and the driveway was slanted, the truck rolled more than desired and contacted a 7200-volt overhead power line, electrocuting the signaler, who was apparently touching the bed of the truck.