The blaze affected two units of a multi-residential building in the 6500 block of North Fairfield.
The fire was reported shortly before 3 a.m., and it involved two upper floor units in the rear of the structure.
Four Chicago police officers arrived on the scene. Their quick action may have saved the lives of some residents and their pets.
"The doors were locked. So, we kicked in a few doors, and brought people out. Two kids," said Officer Forsell of the Chicago Police Department. "We just walked them out?There were flames in the back. There was a lot of black smoke coming out of the apartments."
ambulances stood by at the west rogers park fire scene -- but no injuries were reported. those families displaced by the fire reportedly found shelter with neighbors.
The cause of the blaze is being investigated.