Abstract: An employee's right thumb was amputated while attempting to adjust a truck suspension into alignment at Roy and Dot's Truck Specialties. The company is a repair shop for trucks and is located in Montebello, California. On the day of the accident, the employee started working at 08:00 a.m. and was assigned the job of suspension alignment of a diesel truck in the frame/rack area of the repair department. The right rear axle of a diesel truck vehicle was lifted by one Model 18-004461 Gray Automotive Product jack (15,000-pound capacity, 200 pounds per square inch). The employee was lying horizontally on the floor and facing upward aligning a Hendrickson brand RTE suspension system beneath the diesel truck. The employee completed the first alignment of the truck on the left rear side and began working on the second alignment at the right rear side. During this second suspension alignment, the employee was attempting to place a walking beam between the two perch axles of the suspension system, and then slip a bolt adapter between the three holes. A coworker who witnessed the accident was standing adjacent to employee. At that time, the coworker was handing the employee tools and assisting him. The walking beam was placed between the two axle perches but was not aligned. The walking beam, which was connected to the vehicle, was in the higher position than the two axles. The employee placed his right thumb through the one hole of the perch axle component. The employee was wearing cotton work gloves at the time. The jack, which lifted and held the vehicle in place during the work task, failed resulting in the immediate vertical fall of the walking beam and the vehicle. The metal bushel components being close together acted like scissors and amputated the employee's right thumb. After the accident, the employee was transported to USC Medical Center. Paramedics recovered the right thumb from the glove he was wearing during the accident. An initial surgery and a subsequent surgery to re-attach the thumb were unsuccessful. The employee has extensive work experience performing work on trucks and has performed numerous axle alignments during his employment with the company.