My E1 electrician whom I was apprentice under. Told me a story that he was on the site with the plumber. And the plumber had begun to drill a hole from the inside out. After a few seconds POP sparks and a whole lot of noises and screaming. All the lights flashed and whatever.

My E1 determined the plumber had drilled into the main cable from the meter. So he had to unplug the meter. Oops

KOT