The extra-alarm blaze started just after 3 a.m. in a fast food Chinese restaurant on Cicero, fire officials said. Smoke was still billowing from the building three hours later.
Firefighters were able to contain most of the flames to the original building and get the fire under control. However, some flames spread to the apartments above, leaving an unknown number of people homeless. Residents in nearby buildings also were evacuated.
"We weren't sure as to how many people were in the building, some were on the street. We evacuated a bunch more," said Chicago Fire Department District Chief Timothy Sambey. "No damage that we know of so far to the adjoining structures."
No injuries were reported.
Approximately 100 firefighters responded to fire.
CTA warming buses also were on the scene for those who needed them, in addition to representatives from the American Red Cross. It is not clear how many residents have been displaced.
As crews continued cleaning up, Cicero Avenue was closed to traffic from just north of the Eisenhower up to Jackson, according to ABC7 traffic anchor Roz Varon. Number 54 CTA buses were also being detoured.
More information on CTA changes is available at www.transitchicago.com.
The Cicero exit from the inbound Eisenhower Expressway remained open. Exiting drivers were advised they would not be able to drive north on Cicero while the closure was in effect.
Firefighters said they expected to be on the scene for additional hours putting out hot spots.
Fire officials confirmed they responded to a fire at the same address on December 8. They did not elaborate or draw any connections or conclusions, but the December 8 fire happened at a hotdog restaurant in the same building. It was a grease fire that was extinguished fairly quickly.
An investigation into the cause of Wednesday's fire is under way.