The extra-alarm blaze started just after 3 a.m. in a Chinese restaurant on Cicero, fire officials said. Smoke was still billowing from the building at shortly before 6 a.m.
Firefighters have been able to contain most of the flames to the original building, and officials say it is under control. However, some flames spread earlier, and two nearby buildings also were affected. Residents were evacuated.
No injuries were reported.
CTA warming buses also were on the scene for people who needed them.
As crews continue to get the fire scene under control, Cicero Avenue has been closed to traffic from just north of the Eisenhower up to Jackson, according to ABC7 traffic anchor Roz Varon. Number 54 CTA buses are also being detoured.
The Cicero exit from the inbound Eisenhower Expressway was still open just before 6 a.m., but exiting drivers are advised they will not be able to drive north on Cicero.