One event was during my first year getting paid to turn wrenches, while learning to use air tools.
I had picked up a used CheePee air ratchet with the paddle trigger. Somehow I got my hand stuck between the car's frame and the paddle. The ratchet was stuck on and whooshing air through. A brief moment of panic later, i disconnected the air coupling and managed to extricate my hand. No blood on this occasion.
I recently cut my hand with a hammer. had a big hole between forefinger and thumb, like a pocket. weird. didn't bleed much. all better now.
During that first year of wrenching, one of the old-timers was welding up an oil drain barrel. it had been emptied and wiped, but not soaped. boom.