Eight people who live in the home, on the 7000 block of South Justine Street, said they lost everything.
A fourth firefighter was reportedly injured after fighting a fire in Englewood Thursday night.
Two firefighters were badly burned in the midst of battling the blaze on the 7000 block of South Justine Street, and a third was treated afterward for exhaustion. The injuries to the fourth firefighter weren't clear Friday morning.
Fire Commissioner Bob Hoff said the two severely injured firefighters became trapped in the attic of the 1.5-story home while battling the fire.
They suffered burns to their face, hands and respiratory systems, said Hoff. One firefighter, a man in his 30s with a little more than two years with the department, was listed in critical condition. The second man, in his 50s, was in serious condition, he said.
The pair were taken to Advocate Christ Hospital and Medical Center in "red condition" for burns. They were transported via ambulance to Loyola University Medical Center's Burn Center shortly before 10 p.m.
The names of the firefighters, as well as identification of their engine company, was not released pending notification of family members.
Hoff said it appeared firefighters had a good handle on the blaze when it flared up.
"The fire went up and they were attacking the fire. They were moving in on the fire. They were on the second floor. The officer and nozzelman were on the second floor when this thing lit up on them," he said.
The eight people who live in the home said they lost everything.
Mayor Rahm Emanuel had been notified of the incident, Hoff said.
The cause of the fire hasn't yet been determined.