When a vehicle with front leaf springs is involved in an accident, the plies of the spring may become pushed back, skewing the ply stack.
On a tri-axle Peterbilt dump truck, the 13 plies of the front leaf springs(22) are held together by the center-bolt. (Bolt is not shown in the diagram)
To replace the center-bolt, 2 C clamps are placed on the spring to hold the plies together, the U-bolts are removed, then the truck is lifted by an overhead gantry hoist to lift the spring away from the axle (blue dot). The center bolt has a round head to locate the spring assembly into a hole in the axle beam, so the bolt must be inserted from the bottom of the stack. On this particular spring, that requires raising the spring about a foot away from the axle.
I removed the mangled center bolt, aligned all of the plies with a long tapered punch, and just as i reached in with the new center-bolt, the chain snapped. The end of the bolt crushed thru the palm bone of my index finger and kept my hand from being crushed any thinner than 1/2”.
They took veins from both feet to be used as arteries, skin from my leg, cartilage from the back of my ear, 5 pins thru the bones, and a box of staples and they were able to save my hand.
I was back to work in 4 months and after a few days while welding on a frame, I stopped as a big grin appeared on my face as I thought to myself “Damn, it still works”.
I’ve had to learn how to do things differently. Being my dominant hand, it took about 3 years to really adapt and learn my limitations and train my left hand new tricks that the right had always done. I still eat and write with my right hand though. Wiping requires finer motor skills though. 
Note: You can do a right-handed job with your left hand by turning around, reach in backwards and close your eyes.