Here's a quick quiz: at what point did I decide it was time to quit working on the kitchen for the day? If you guessed "when the flatbar broke", you're right! I knew it was theoretically possible, but didn't think it would be quite so easy.
I don't use a flatbar for pulling nails very often; usually it's just my framing hammer and if necessary, a cat's paw to get it started (one of these days I'll have to do a how-to post on the right way to pull a nail). Only rarely do I use the flatbar to pull, and even more rarely the long end. Anyways, this was one of those mysteries of our house, a 20 penny nail where normally it would be a 16. It was in a channel between two studs where one of the old front porch walls met the outside wall, so my hammer wouldn't fit. I tried the short end of the flatbar (which has more leverage) and couldn't get it, so I tried the long end braced against one of the studs on the side, and there was a *tink* and it snapped. No injuries, but I stood there stunned for a second, trying to figure out if what I thought had happened had really just happened. Alas, it had.
The really bad news is not the flatbar (aka a Vaughn Superbar), but why I was deciding to pull that nail is that I thought I saw some tell-tale termite droppings along the edge of the channel. Tomorrow I'll go ahead and pull out the boards involved just in case. I did get the final bit of the ceiling drywall pulled down, puzzled over some more on where to run the plumbing (particularly the vent stack), and placed a few electrical boxes for countertop outlets and such.