The single-digit temperatures created dangerous and icy conditions Friday morning for firefighters.
In Chattanooga, 15 fire trucks and dozens of crews had to help put out a large fire at an apartment complex. The fire displaced 75 people, destroyed 12 apartment units, and damaged 54 more.
The frigid temperatures created an extra hazard for firefighters who had to stay warm.
Fortunately, there were no serious injuries.
Investigators believe a discarded cigarette butt likely caused the fire.