.....using a charcoal grill on a wooden porch or deck.
Last night I roasted a chicken on our Weber kettle. When I took it out, some juices drained out. I didn't pay any attention to this at all. Not a big deal. Later, I looked outside and found the wheels of the kettle in the final stages of burning off. All I can figure is that the juices (melted fat) caught fire, drained through the bottom and did the deed. In more than forty years of using Weber kettles we have never had an incident like this. Had this been on a wooden deck, it could, very well, have resulted in a house fire. Luckily it was on gravel outside my shop and ended up being just funny.