Nice collision effect. I am actually in the middle of a "rigid body" work, I have just applied a bullet animation. Have you tried to make the both builldings collapse at the same time? By the way, could you tell me how did you do to insert your video directly on blendswap. I can only put a link . Thanks Nice blend

You mean collapse completely after impact? & all you have to do is post it on youtube and then copy the link to your youtube video and paste it where the description box is. it will look like a link at first but once you upload your blend it will convert into a streaming video.

I mean : two buidings falling down at the same time, not one on the other. Thanks for tips, I fixed it. I had the link but this link must have its own line.

How long did it take to do this? It's really complex, and really well-done.