The simulation of the two trucks colliding was done by using 7 different trucks, and green screen. The two main ones that collided were specifically "damaged" for the scene using special decals and other equipment. To make it look like 51's truck rolled over for the quick shot, it was attached to 2 plow trucks by a rope, going in opposite directions, and slowly pulled forward and rolled over on it's side at the same time. The remaining trucks were used for the driving shots, and interior shots of the guys getting hit with fake broken glass, in front of a green screen.
Goof: At 31:50, Dawson bumps the brick wall next to her. It easily shifts and you can tell it's really made of foam.
1360 S. Blue Island Ave. (fire station)
Columbus Drive Bridge, N. Columbus Dr. & E. Wacker Dr. (bridge accident)
820 N. Franklin St. & W. Institute Pl. (burning building)