Inspired by the very similar thread about school incidents.
A coworker set the break room on fire by microwaving her lunch for 30 minutes instead of three. No idea how you forget your lunch is in the microwave, let alone for half an hour, but hey I got to go home early.
I once microwaved a bowl of cereal by mistake instead of a bowl of stew.
Cereal goes on fire and smells like burning horse hair when microwaved