The controlled burn story may not be correct. There is a small structure that's 50-ish yards from the hanger that was slated for demolition, and I had heard story from different sources that a controlled burn had gotten out of control, but that apparently wasn't the cause. For now it's "under investigation." The building itself wasn't exactly fireproof. The main bulding was all wood (it was built at a time when metal was in short supply) and met 1940's standards. The plan was to have a new structure in place soon, since upgrading the old building would've been prohibitivly expensive.
Yankee air lost several planes to the fire. An F-105 that was undergoing restoration to become a static display, A Lockheed Loadstar, their OV-10 Bronco, and their glider were unable to be saved. The B-17, B-25, and C-47 are all ok, and more importantly, there have been no injuries reported. Apparently the C-47 had to be pushed out by a handful of crazy/brave folks. It will need new engine cowlings, since both of those are still inside what's left of the hanger.
Not a good day, but it could have been far worse.