All the victims suffer from smoke inhalation, Chicago Fire Department officials said, and were taken to local hospitals. Four are in fair condition, two others are in good condition, CFD said.
The fire broke out on the second floor of the five-story building around 10:30 a.m. Wednesday. While the fire was mostly contained to that back unit, the smoke spread quickly.
"A lot of black smoke. I couldn't see anything at all," Jacob Ivankowski, resident, said.
Chicago firefighters used ladders to reach residents on the upper floors. Most were able to leave on their own through the stairwell and gather in the lobby of the building next door for warmth.
One firefighter received minor injuries.
Sheridan Road was closed to traffic in the area.