Abstract: At approximately 11:30 p.m. on June 21, 1988, Employees #1 and #2, a son and his father, who were principals in a local transit bus operation and had more than 10 and 40 years work experience, respectively, were replacing the lower rear radius rods on the rear right side suspension system of a 1969 GMC 51 passenger company bus. They were on the street in front of the garage. One radius rod had been replaced but had yet to be attached when the 44,000 lb rated capacity air operated jack slipped from the bellows support beam on which it had been placed. The bus dropped onto wooden shoring that had been placed below the chassis frame, shearing a 6,000 lb capacity jack stand. Employee #2, who was working under the bus, was pinned under the rear axle. Employee #1, who was handing Employee #2 a wrench, was pinned on his back with his lower body under the right rear door area of the bus. The employees were not removed immediately. Employee #1 was pronounced dead of mechanical asphyxia on arrival at the hospital. Employee #2 sustained a bruised chest, thighs, hips, and right arm. He also required 11 stitches on his right elbow. The jack that had been used had no block between the small flat jack cap and the lifting point.