I have some very large structures, and I have a tendency of pushing the limits of structure integrity. So far that, in one of my larger stone buildings I wanted a flat roof made of stone flooring over the main hall and, no matter what I did, I could not get the last piece in the center to stay. I finally built a fire under it and called it a chimney! :-)

All that to say that I have never, even with fully side-supported stone with no supports blocks that are in the deep red, seen anything just pop like that under any circumstance. I think the last time I had a building piece spontaneously fail was way back with my first large wood structure when I tried to build the roof too high. The center roof pieces failed due to (presumably) weathering after a time.

I've built these structures on local worlds and multiplayer servers, so I don't know what might be different between our configurations that might cause it. I suppose chunk boundaries could have an affect. I suppose I might have avoided those conditions. I'll have to poke around and see if that might be the case.