So I’ve modeled the bridge and have the particle dynamics ready as well. Figuring out the dust was tricky though… Here is how it works: particles need to be activated along with the animation. In other words when the bridge falls the dirt and dust needs to dissipate into the air.

Particles can be placed on any 3d surface but to get them to turn into dust as the bridge falls, I’ve set up an operator that checks the speed of the particle. So when the particles are on the bridge they are still, but when the bridge falls the particles fall and begin to pick up speed! Then any particle that is moving will then turn into dust. More testing underway. This is a procedural way to animate effects, instead of keyframing all of these operations they are dynamic instead.
I’ve also got a few holiday tutorials coming, so stay tuned.