I've had a busy morning; I meant to comment earlier.

A "drill" wherein Chicago is evacuated (dirty bomb? metorite strike?) would cost millions of dollars, result in the wholesale destruction of empty neighborhoods by fire, and kill a few dozen people. Regardless of potential threat, a drill evacuation won't happen. I'll go out on a limb and say that I'd resist to the best of my ability an order for a "test" evacuation of my home, much less my neighborhood.