Another picture from my collection, this one is the back side of a power supply module from a Broadcast Electronics AM6A transmitter:

It happened during power up from 1 KW to 5 KW and it was quite loud, as I was standing right next to the transmitter. The exploded part is a 0.1 uf capacitor that looks like an add on. In fact, some of the other power supplies don’t have it. It also took out the 20 amp slow blow fuse.
I like the exploded look of the board, kind of like on The Road Runner, when Wyle E. Coyote looks into a box and something explodes.
This is the only problem I have had with this particular transmitter.