When I was 10 yrs old, we had an old 10-20 belted up to a feed grinder, grinding corn to feed the cows. Something jammed up, and dad jumped the belt to kill the tractor before everything broke. Caught his toe under the belt, and it flipped him head over heels, and he came down on his head. Was laid up all winter, and two years later was diagnosed with brain cancer, which ultimately took his life. When he was a young man, he had been kicked in the head by a mule, and had never suffered any consequences from it. The doctors said that a small tumor had formed from the kick, and some 30 years later, the belt accident had aggravated that dormant growth, and resulted in the cancer. As I recall the grinder cleared itself, and went humming along until I was able to shut down the tractor. That was 65 years ago, and I can still see him tumbling through the air.