Witnesses say the flames erupted without warning inside the home just before 9:00 a.m., prompting them to dial 911.
"The neighbor upstairs said she heard a loud popping noise and I think she's the one who called 911," said Jason Stolzenbach, resident.
"The police came and they told my son and daughter to go outside," said Maricela Munoz, resident.
Firefighters arrived on the scene to escort residents out of the building, and also assisted the police officer who helped rescue the woman. Both the officer and woman were transported to an area hospital, where they were treated for smoke inhalation.
"He was beat back by the heat and smoke. . . Our guys went in and quickly got others out," said Oak Forest Fire Chief Terry Lipinski.
"I'm just glad everyone got out safe. It's pretty alarming to wake up to that," said Juan Munoz, resident.
Authorities are investigating the cause of the fire. According to preliminary reports, the fire started in the living room of the second floor unit.
The property manager said the other units sustained minimal damage because fire walls were installed.