Abstract: A temporary driver and a helper were delivering a load of roofing material. The 1994 Ford Truck L8000 had a Clearfield Conveyor-Boom installed at the rear of the flatbed on the truck. The delivery site was a residence, and the delivery had to be made from the backyard, where an overhead power line was located. After the driver backed the truck into the yard, the two employees unsecured the boom from its traveling position and swung it around behind the truck. They then backed the truck on an angle to the house going between two groups of trees. When the truck was close to the house, they raised the boom so that it would reach the upper roof area. They unloaded a skid of shingles and then lowered the boom to a lower roof area, where they unloaded felt paper. The rest of the delivery was to be placed in the front yard. To do so, they planned to back the truck up the driveway and unload the truck by hand, stacking the load on the ground. After the helper came down from the roof, the driver moved the truck forward a short distance and stopped. The helper lowered the boom a little bit so it would not hit the edge of the house. With the helper on the ground, the driver drove the truck down to the driveway, stopping it when the cab was almost at the end of the yard. (The helper did not believe that the boom was within 3 meters of the power line at this point.) Thinking that the boom was too high, the helper climbed up on the flatbed to the controls for the boom. He tried to lower the boom, but could not. The boom had contacted the power line. The helper heard a humming sound and felt an electric shock. He jumped as far as he could from the truck. The driver, who was in the cab, opened the door and stepped out. He was electrocuted. (His clothing also ignited.) The engine, the cab of the truck, and the tires ignited. The helper complained of a tingling in his back and shoulders Emergency medical services transported him to a hospital, where he stayed overnight for observation. He was released the next day. (The helper did not return to work because of psychological problems caused by the accident.)