I had some central AC installed in my attic recently, and a short circuit (or some event) occurred when one of the two 240V circuits were switched on. The circuit breaker did not trip; the installer had to manually switch the circuit off to stop the event. The lightbulbs dimmed in the house, my cable TV was fried, and I noticed what turned out to be a leak in my main water pipe under the foundation.
I have a boiler system for heating, and I'm thinking the short circuit leaked current across my boiler pipes and arced over to the water line and poked a hole in it.
I've been told that this is possible, but I'd like to know for sure.