Aliens killing the network?
We had racks in a data centre, as you do, and we had a load of new supermicro servers all set up and ready to be deployed to do useful things (like spam filtering).
And we lost power - killing the whole service for some minutes until power was restored and everything booted.
The reason - aliens!
Well, actually, more a question of load testing the new servers running the SETI stuff. I think we managed a passable ranking at one point with that.
I remember running the SETI command on the last box, and oddly not getting any response to my command, or, well, anything.
Moral of story - always make sure you put kit in well within the current limit of the supply and the circuit breakers, FFS. A lesson to learn early on.
These days we have racks full of FireBricks which are hard pushed to use 0.1 amps even on dual supply when running flat out and shifting 2Gb/s of traffic, so not such an issue.