I think that last night counted as the most interrupted role-playing game ever.
I was running an installment of my ongoing modern horror/conspiracy game for ashacat and taichigeek; a contemporary reinterpretation of that grand old Call of Cthulhu book adventure The Haunted House (a.k.a. Corbitt's House). We had just gotten through the preliminaries when my pager started buzzing with automated 'device down' messages, a lot of them. I was taking sidelong glances at my laptop trying to figure if this was something that I needed to do something about right now when the phone rang. It was one of my fellow managers, who was already at City Hall -- the locus of the trouble. Workers doing Asbestos abatement in one of the building's four main riser shafts had cut off power to the shaft they were working on, and accidentally killed power to the building's main network room.
Over the next hour I must have been on the phone a half dozen times. The situation that unfolded got pretty interesting. It was discovered that earlier in the day, the City electrician had ID'd the wrong breakers, such that when the abatement team killed the power they not only turned off the juice to our MDF, but they turned off the power to the wrong riser shaft. Meaning, that the problem could have been much bigger than the loss of phone/network service in a handful of buildings. The abatement workers wanted the power off in the riser shaft they were working in because they were pressure washing it. You know, with lots of water. Thankfully, no one got hurt and I didn't have to go in -- the abatement crew got the power turned back on, no one got zapped, and the Boss went in to handle the people side of things -- but the disruption was far from helpful. Work with me people, I'm trying to create a little mood here!
...The rest of the game went alright, though I don't think we ever quite got into a good stride. But, I did get to hit them with all of the Corbitt's house classics -- the magically motivated bed that knocks one of the PCs out the window; the swarm of rats that pours forth when the party breaks down the wall in the basement; and the ghastly animated corpse of Corbitt himself (a.k.a. Graham Gimli in this game). And, in the end, the PCs triumphed by a whisker, with taichigeek's investigator Karl on the verge of death and ashacat's PI Vicky good and gouged up. The closing scene ended with Vicky sitting next to Karl's hospital bed, after a long conversation, Karl looking over and wheezing out "so, are we partners?"