Abstract: Employee #1 was a mechanic with four years experience in bus repair. He was working on a bus in which the left "tag" wheel tire had experienced a blowout and the resulting debris had damaged the undercarriage. Employee #1 raised up the left rear axle of the bus using a vertical piston, single-point type jack. He did not place a block between the jack's cap and the bus axle structure or crib the axle to prevent it from falling. After jacking up the bus, he removed the "tag" wheel and then was going to replace a broken wheel stud, some lines, and a damaged shock absorber. Employee #1 was apparently removing the brake drum to reach the wheel stud when the bus shifted or moved on the jack and the axle structure fell. When the jack fell, a sway bar landed on the Employee #1's left hand and chest. He was pronounced dead at the scene.