Playtested yesterday and had a first-time experience happen:
I was the defender holding three remaining victory buildings. The one that was the focal point was a two hex wooden building. I dutifully had units in each level of the two hexes--one hex had two squads and a hero on the ground floor, a concealed leader and a halfsquad on the 1st level. I felt confident in a win, as I was loaded for bear and my plan had come together.
Well, my opponant had one of those "throw-away" tank--you know the one, a tank that had broken its MA and was too valuable to risk repair. He had driven it up in and left it in motion adjacent to the building hex the prior turn.
So he decides to overrun the lower level. Bog DR is a 1, 3, and the hex rubbles. I lost 2.5 squads, an 8-1, and a hero to one lucky DR. I did manage to hold on to win, though.
First rubbling by AFV in my entire ASL life, although I have seen a number of tanks fall into the celler.