Abstract: On July 13, 2004, Employee #1, a mechanic, was assisting a coworker in the replacement of a leaf spring assembly. A leaf spring assembly, which weighs between 150 and 200 pounds, consists of a stack of steel plates attached between the axle and frame rails as a suspension device to support the load of the truck and control the handling and drivability of the vehicle over the road through various conditions such as dips, bumps, and other terrain features. The vehicle being repaired was an LTI 100 Class 2250 Aerial Ladder fire truck. Only the left side of the truck needed to have the leaf spring assembly replaced. However, in order to conduct the alignment, both leaf spring assemblies needed to be released of their tension. Employees #1 and the coworker released both spring assemblies on the left and right side of the truck, and then replaced the leaf spring assembly on the left side of the truck. After that was completed, they proceeded to compress and realign the right side leaf spring assembly with the C-clamp on the helper spring and the radius leaf. The helper spring leaf provides a progressive spring rate and additional stability over harsh terrain and road conditions, and the radius leaf attaches to the spring assembly and the forward spring mounting bracket to hold the axle in alignment with the chassis. The leaf spring assembly, helper spring leaf, and radius leaf all work together and connect the rear axle to the frame of the truck. Employee #1 was lying on his back on a creeper, a flat board with wheels to lie down on when working underneath a vehicle, with his feet extending out the right side of the truck, and his head was positioned towards the center of the truck. The accident occurred when Employee #1 used his finger to check the alignment of the leaf spring hole and bracket hole, which was approximately 1 to 1.25 inches in diameter. At that moment, the clamp that was compressing the springs slipped. The C-clamp moved to the main spring assembly from the helper spring. This release of energy moved the springs apart, and Employee #1's left middle finger was amputated as the metal pieces shifted from an aligned to a non-aligned position, acting like a shear.