Abstract: Employee #1 and coworkers were repairing a jammed mast on a battery/electric walk-behind forklift of an unknown brand that had been purchased without identification marks. The mast guide blocks came out of the rails and the bottom, and were resting on a crossbar. The forks were approximately 3 ft above the floor. Employee #1 was standing on a battery box facing the mast, pushing on the cylinder to align the blocks with the rails. When he pushed outward on the cylinder, the cylinder and blocks moved from behind to in front of the rails. They went too far and the cylinder, blocks, and mast fell, causing the crossbar to move. Employee #1's right hand was almost completely amputated when it became caught against the main mast fixed crossbar. The jammed mast had not been blocked up, and extension tools were not used to push the cylinder.