As it is right now, when a structure falls it just all stays in one piece as parts of it clip through walls and other objects and no matter what you do it will always have the same rotation as it falls and never be hit off in a direction. I thought that it would while that works for things that have just been cut from their supports (kinda), it does not for something like grenade explosions where it could fling pieces of the 3x3x3 block that it can destroy into other things. of course grenades are not that power full but i still think that other explosions that may be there in the future should have this ability and structures falling should be able to break up as well. And something that would hugely compliment the new realism of the wall breaking would be its ability to break other objects as it falls through the air. I don't think i need to explain this part.
Example: Wall A falls through the air and breaks apart. Piece 1 of Wall A hits Roof B and it caves in. Roof B travels with less force and does not take out the bottom of the suspended sniper nest. Piece 2 of Wall A flies a few blocks to the side and misses Roof B. It instead takes out the horribly designed bridge holding up the nest killing all of the survivors of the roof cave in.