The fire broke out in the 2300 block of West Chicago Avenue in Ukrainian Village.
Chopper 7 was over the scene, where multiple CFD firefighters could be seen on a building with flames and smoke shooting out of the roof.
The main fire was put out just before 3 p.m., CFD officials said. No injuries were reported, but some pets were lost.
No further information about the cause of the fire was immediately available.