physics settings for simulating a controlled explosion with fracture

I have been experiment with the fracture features and physics, I have found quite a few good tuts especially this one, but I’m new to physics, logic bricks and what not in blender and most of the tuts focus on blowing shards outward what I would like to do is have buildings collapse/implode as in like a controlled demolition but I not certain about the physics settings for that.

thanks in advance