Abstract: On June 12, 2002, Employees #1 and #2, and a coworker arrived at a two-story banking complex to start reroofing a portion of the building. The site superintendent was also observing the operation. They backed a truck into the bank drive-thru service area and parked parallel to the teller windows, with the back abutting an air tube and electrical conduit bridge. They intended to use the bridge as a means to gain access to the roof. The truck bed could be elevated for use either as a scissor lift platform or as a dump truck bed, and they intended to scissor-lift the bed to the level of the conduit bridge. Employee #1 and #2 got into the truck bed, while the coworker stayed in the truck cab to operate the truck bed controls. Employee #1 was at the left rear of the bed directing the control operator, while Employee #2 was positioned in the middle of the bed. The truck bed began to rise. It had reached a height of approximately 10 ft when it unexpectedly went into the dump mode; the rear of the bed suddenly dropped to the frame and the front pivoted upward. Employee #1 was ejected from the bed and landed approximately 20 ft behind the truck, striking his head on the concrete drive. He was killed. Employee #2 slid down the bed with the equipment and roofing material and landed on the concrete drive; he suffered multiple contusions and abrasions. The dumping action was apparently caused by defects in the elevator and dump control system. The control system allowed the left side of the scissor-lift to come out of its channel and roll along the channel top, while the right side remained in its channel. For some reason, the hydraulic cylinders imposed a left-bearing force, causing the right side of the scissor lift to come out of its channel. The front of the lift frame then swung upward to the front of the bed while, at the same time, the bed pivoted, with the front going up and the rear down. The defective control system was due to insufficient inspection and maintenance.