I had two at Maastricht. One was when the mains power was cut, the diesel generator suffered a hydraulic lock and blew the cylinder head through the roof and then the Tech Watch Supervisor managed to short out the batteries.
It went very quiet and very dark in the Ops. Room.
All data/phone lines etc coming into the building are duplicated and run on different routes. Only where they enter the building do they come together. Guess where a contractor dug a hole. Again very wuiet, No radar, no R/T, no phones - at least that time we had lights.
Fortunately, we had very few problems in a stripless environment. The few we had when I was there, there was enough time on a frozen picture to jot down essential information before switching to a much improved back-up system. Nowadays all that info can be printed out on the sectors.