A microwave oven fire
A family member wanted to warm up a biscuit and thus placed that biscuit on a plate and put it in our microwave oven. The biscuit caught fire inside the oven and the flame broke the plate in half before extinguishing itself (thank goodness). The whole house was permeated by smoke.
The biscuit had been utterly dry. There was no water in it. Therefore, instead of the microwave energy having some water to work on, arcing occurred (so I think) within the biscuit causing it to ignite.
I happened to wash the broken plate after the event happened, but now I rather wish that I hadn't. It was one heck of a sight after the biscuit fire and would have made for a more dramatic photograph than the one you see above.
Still I would offer the following advice. Make sure that everyone in your household knows that a microwave oven interacts with water. You don't ever want to replicate what happened over at our house.