Abstract: At approximately 8:40 a.m. on December 18, 1991, Employee #1 was checking and adjusting the car's wheel alignment under the alignment rack when the car moved forward and dropped about 2 ft into the pit. The employee's upper body was pinned under the wheel bar. He was hospitalized. Employee #1 was a working partner and has about 25 years of experience in wheel alignment. No defects in the equipment or faults in the safety procedures were found. Wheel chocks are now being used as an added precaution to prevent the car from rolling off the alignment rack. The employer could not foresee the accident.