I thought this might be a fun topic, since mine was tonight!

I have a unit that has a tenant moving in next week - everything is paid for and signed, and all that's left is to deliver the keys. I went by the house tonight to pick up a few odds and ends that were lying around from the in-between tenants phase - the step ladder, broom, cleaning supplies, etc. While I was there I ran the central heat to burn off the dust that collects when a heating unit hasn't been run for 7 months. Heat works great, I turn it off. Have most of the lights on and am collecting stuff when all of a sudden the lights go off, and don't come back on. So I go out on the porch and it looks like the neighborhood power is off, though it's daylight so it's hard to tell. I go back inside and the stove light is on, but no other lights are on. What? So I go around checking the house and almost nothing works, but a few things do work - the refrigerator, for example, but not the stove. 

I go down and look at the breaker panel and determine that essentially everything that isn't working is on one bus, and the things that take 2 busses (stove, for example) don't work either. I flip the main breaker a few times and all the individuals, but nothing changes. Oh crap! One bus on the breaker panel has died!

So here I'm trying to figure out what I'm going to do (the walk through is tomorrow!), how I am going to get an electrician out there to replace the breaker panel in the morning, when I notice that the electric meter was flashing. I go back on the porch and all of a sudden all of the power is back on, and I see lights come on in the houses across the street.

The power company had one leg of the service go dead to the neighborhood! DOHHH!

Tragedy narrowly avoided, though I was halfway through a full-blown heart attack!

So what are your "Oh Crap!" stories?