Three people were treated on the scene for smoke inhalation when a fire started at one home and spread to two others overnight in the South Chicago neighborhood on the South Side.
The blaze started about 3:20 a.m. in the 8500 block of South Saginaw Avenue and spread to two adjacent buildings, according to Fire Media Affairs spokesman Quention Curtis.
At least of of the buildings was vacant.
"It was elevated to an extra-alarm immediately," Curtis said. Three people were treated on the scene after they complained of minor smoke inhalation.
No one was hospitalized and while the three 1-1/2 story frame construction residential buildings sustained "heavy damage," they remained standing, Curtis said.
The alarm was canceled at 4:20 a.m.
A 2-11 alarm sends at least eight engines, four trucks, two tower ladders, five battalion chiefs, a district chief, a deputy district chief, a squad company, an ambulance and the Command Van to the scene.