One of the more drastic things that can happen in a nuclear power plant is what's known as a LOCA, a loss-of-coolant accident. I like to refer analogously to some of the more drastic things that can happen to electronic equipment as a LOMS incident — Loss Of Magic Smoke.
This is particularly relevant today because that's what just happened to my main uninterruptible power supply, an APC SU3000RM3U which powers both of my workstations as well as my server/network rack.
As close as I can figure out, the capacitor just to the left of that power blade failed first. (You can see another matching one about an inch behind its mortal remains.) This was the first muffled bang I heard, and everything lost power at that exact moment, which is probably why nothing powered by the UPS was damaged when that row of power transistors went into runaway and blew up in a ripple about eight seconds later, creating a second, much louder and sharper bang. Not only did they vaporize their power leads, they blew several holes in the top layer of the main board. This was the point at which the magic smoke began to drift out from the front of the UPS.
The UPS, of course, is toast. And it was only last year I managed to locate a matching expansion battery chassis for it...