Maybe we could turn this into a “Stupid Shop Fires I’ve Started” thread. I’ll go first.
I was welding at my work bench the day after having done some painting. The trash can that had my discarded paper towels (soaked in paint thinner) that I used to clean up and it wasn’t far enough away. It was a small plastic trash can and mostly empty except the paper towels. You know it’s hard to see flames roaring out of the trash can when your welding helmet is down. Anyway, I carried the trash can out while it was on fire and set it on the driveway. It burned down to almost nothing, but a puddle of plastic. I promptly forgot about it and went back to welding. Then the wife came home and said “What’s that on the driveway?”
Now days, I have several 5 and 10 pound fire extinguishers around the shop as well as three 2 gallon water cannons that stay pressurized. All are properly hung near the doors where everyone knows where they are. My welding trailer has three fire extinguishers (one regular and two water cannons) and my home has three 5 pounders. I now use a dedicated metal can with a metal lid for my combustable rags. I guess I learned something after all.