I've seen it happen on a 50cc YAK and it drove the landing gear up through the fuse and cracked most of the bottom stringers from about half way back all the way to the front. It also bent the wing tube, the plane was repairable but barely. The pilot was trying to pull out of the spin very low for effect and the engine burped and died when he hit the throttle. It was about 50 to 60 ft up when the engine died and it spun to the ground with a big thud.