On Wednesday, August 1, around noon, I was on the summit of Stratton Mountain taking a break below the firetower. I saw a large black bear approach the GMC Caretaker Hut from the south. The bear attempted to break into the hut. The bear broke off a piece of the door. The bear looked over at my direction, saw me, and disappeared. The whole encounter took ~15 seconds. The caretakers were not there. I was the only one on the summit at the time. No photos of the bear. Sorry. The folks at GMC have been notified.
Here is a photo of the broken door: