At work, we had a USB drive full of Ghost images. Someone else didn't know how to use Ghost that well and they managed to nuke the partition table by trying to write an image on the USB drive onto the drive itself... or something like that anyhow (newer versions don't let you do that any more, I note). Fortunately, they didn't destroy the data itself.
I rebuilt the partition table and saved all of our backups.
That's like the time my supervisor was done setting up a server, and then was going to image it. He had two identical drives in the machine and imaged the empty to the full drive instead of vice-versa... I was the one to cleanup the mess, but learnt a lot.
I rebuilt the partition table and saved all of our backups.