Abstract: At 9:30 a.m. on September 14, 2021, an employee of a crane maintenance company was injured while working alone in the maintenance shop at a marine cargo terminal. The company provides repair and maintenance services for on-dock and shore-based ship loading, unloading, and cargo handling equipment at major West Coast ports. The employee was replacing a damaged rear spring hanger assembly on the suspension of a bomb cart. While positioned underneath the cart, the employee removed the center safety bolts and cut the U-bolts securing the assembly. Using an impact gun with an 8-inch socket, the employee began removing two nuts and bolts. To stabilize the tool, the employee cupped their left hand under the impact gun handle. As the nuts and bolts were removed, the spring tension released, causing the rear assembly spring to drop toward the concrete floor. The employee's left hand was pinned between the impact gun and the floor. When the leaf spring returned to its resting position, the employee was able to drop the impact gun and free themselves. The employee immediately notified a coworker, who was also the supervisor. The coworker transported the employee to the company clinic, where they were referred to a hospital for treatment of crushed fingers on the left hand. On September 24, 2021, the employee underwent surgery for an open fracture with tendon and nerve damage to the middle and ring fingers. The employee was discharged from the hospital on September 25, 2021.