Re: the picture in the article
On that note...
A friend of mine was a farmer (no, he's still extant, just not farming these days) and was in the barn using an angle grinder to do whatever farmers do to heavy machinery. After a while he noticed that the sparks had ignited the diesel-soaked crotch of his boiler suit.
It didn't take much thought to conclude that, while extinguishing the flames would be prudent, the 9,000 rpm device he was holding could prove hazardous. The lead was long, so he through it a considerable distance down the barn. Unfortunately it landed disc-first and facing in the 'wrong' direction. The disc dug into the concrete floor and the apparently irritated device raced back towards him, intent on mayhem.
It ran out of steam, but only after reaching his right shin and penetrating to the bone. It took considerable presence of mind to extinguish the flames, make his way to the car and drive himself to hospital without passing out. There were no long-term ill effects, barring a very ugly scar.