Detecting potential secondary collapse

[BigRig]

What device do you use to 'measure' the potential for a secondary structural collapse?

[ADSNWFLD]

Our team has a Rotary Laser. It allows us to monitor a wall and detect any movement. It is a Level, Plumb & Square Laser. We don't use it too much but it is a great tool.
I've also practiced with a Transit and that works well also, the laser is just more high tech.

[BigRig]

I've used a laser level also. Its a great tool for the purpose. Another note, I've used a magnetic protractor to indicate movement of a larger vehicle onto a smaller one after a collision.