This one happened in my 1st day working in the university where I work...
I was still knowing the place and all, there was 2 guys (One of them a friend of mine, he who arranged the job for me) showing me the place.. then some boxes arrived, I dont remember what were in those boxes, and we had to store them in the DEPOT.. the depot is a small room with DOZENS and DOZENS of computer stuff, (Ya know, computers, monitors, keyboards, mouses, and stuff like that). The boxes were supposed to be in the top of a shelf there, so this friend of mine climbed in a table to reach the top of the shelf. On the table there were like dozens of computers piled up, and a few monitors. As soon as my friend jumped out of the table, I think you can guess what happened.. the table just turned over and collapsed, crashing all computers and monitors into the ground.
The noise was just TOO loud, and we were just like "FUUUCKK!! WE ARE SCREWED!" .. and it was just my 1st day in the job. We phoned the boss and said "We heard a noise in the depot, and when we went there, the table had collapsed!" . The boss said "Well, test everything and clean up the mess".
Luckily enough, all computers were working nicely. Nearly all monitors suffered some damage, most of them just in the case (now you can see the inside of most of those monitors without having to open them), but just 1 or 2 stopped working. And it was lots of work to clean up all the mess