The carefully planned generator that was meant to keep the core servers running during the power cut, died due to earth leakage. The UPSes let the servers down gently, but they were still down for a while.
And oddly, we managed to blow a lot of fuses somehow. Admittedly, some of them were 1 amp fuses and it doesn't take a lot to kill those. (somehow siskin now needs at least a 3 amp fuse when it has lived on 1 amp for months). We also managed to blow a few power supplies in a room which was totally isolated. The mind boggles.
Anyway, things are mostly working now.