Early 90s, Culpeper Virginia.
An infamous high-power flyer, "W.R.," had flown in. This guy who was rumored to have been in a car accident and gotten a head injury but in retrospect had what we'd call a "spectrum" disorder. He arrived with a large model which he'd cut apart so it could be carried as luggage and then been hastily reassembled. It was powered by a cluster of big motors, I or K perhaps.
Most vendors had become familiar with WR's reputation, and refused to sell him motors. But a private party was willing to; they sold him "iffy" motors, some of which had their aluminum cases dented.
The RSO allowed him to fly, but called a heads-up. I was on duty and walked around the perimeter and told people to stand up and get read to run.
Hah! It was a good call. One of the motors cracked its casing, and another cut loose from its moorings. The largest part of the mess fell not far from me. I could see into the split casing and the still-burning fuel grain. A little blue inferno. It wasn't HORRIBLY dry, but there were some fires to put out.
The multi-level certification system we have today was spurred, in part, by the participation in the hobby of guys like W.R. There were others, the ones responsible for high-powered models tearing to pieces or plummeting to earth. But I think poor incompetent W.R. was a catalyst.