Firefighters arrived on the scene around 6 a.m. to find the apartment building in the 7000-block of South Wabash Avenue engulfed in flames.
One man died and three other people were transported to hospitals, CFD said. Their conditions are not known.
The fire started in the bedroom of a second floor unit of the victim. Residents left trapped by the fire were able to escape through the back of the building.
"The room of origin was in the bedroom where the victim was found, so it was in the bedroom," said Deputy Chicago Fire Chief Walter Schroeder.
Fire officials said there were no working smoke detectors in the four-flat when the fire broke out. Calls to 911 for help began around 6 a.m.
"I couldn't really see anything, it was just really scary," said one resident, who did not want to be identified.
The resident said she's only lived in the building for six months. She awoke to the smell of smoke and sound of firetrucks.
"And I tried to come out the front and I can't get out because the firemen were already in the hallway going up to the second floor," she said. "So I go back in and go to the back door and I run out the back door."
Neighbors said the victim is a man in his late 40s whose birthday was Wednesday and that he may have been celebrating when flames broke out.
Four victims at still and box with plan one. Three transports one fatality an adult male. pic.twitter.com/LoJkop2Vcx— Chicago Fire Media (@CFDMedia) August 14, 2019
The fire remains under investigation as the department passed out smoke detectors in the neighborhood.