The fire started in the basement of a tax preparation office shortly after 2:00 a.m. on the 500 block of South Clinton Avenue.
Officials say the flames spread through the walls causing smoke damage to several apartments.
Firefighters were able to get the blaze under control in just over an hour.
Two people were taken to Saint Francis Hospital for evaluation.
It's not clear on how many people were displaced or what sparked the blaze.
