Two homes --including the one where the fire started-- were destroyed. One person was injured.
The blaze broke out in the 200-block of East Cermak Road. Authorities said that homeowner suffered burns and was taken to the hospital.
The first alarm was called for at 2:38 a.m., according to Fire Chief Ken Heberer.
When firefighters got to the scene, the original home was fully involved in flames, and the second home "was well-involved," he said.
The fire went to a third alarm, which brought in about 15 fire departments, Heberer said. In all, about 70 to 75 firefighters were at the scene, he said.
Heberer also said two other homes were damaged by fire, but are livable, he said.
"It took us 45 minutes to get (the fire) under control and approximately two hours before the fire was completely out," he said.
Early Wednesday, firefighters were expected to remain at the scene for several more hours.
Heberer did not have any information on the injured homeowner's condition.
The cause of the fire was not known later Wednesday. The investigation is being handled by the state Fire Marshal's office and Braidwood police.
(The Sun-Times Media Wire contributed to this report.)