Worst computer disaster: Fire.

Worst linux screwup: had a link to /mnt/hda1 (Windows) in /home/user. Tried to delete the link with right click & delete from Konqueror while /dev/hda1 was still mounted....

Dumbest move: Was using a early PC laptop (DOS) at work, computer was specially purchased to program our industrial PLC's. Screwed something up (don't remember what) & crashed the system. Next boot had an error message about damaged files and 'do you want to recover lost files'. So I said yes and entire system was turned into 000001.rec, 000002.rec etc files. We had no backup disks....