Abstract: At approximately 9:45 a.m. on November 8, 1988, Employee #1 was aligning his Mack roll-off truck to a dumpster for pick up. When the rails were fully extended, the steel-jacketed rubber hose leading to the left hydraulic lifting piston failed. A witness saw Employee #1 leave the truck's cab and climb onto the hydraulic reservoir tank and then onto the vehicle's chassis. He was apparently kneeling on the chassis trying to shut off the main hydraulic valve when he was struck and pinned beneath the descending rails. Employee #1 sustained broken ribs, a partially separated aorta, a broken pelvis, and a broken left leg. Employee #1 had been a fill-in roll off driver for 16 months.