Officials were called to a bungalow at the 600-block of South Artesian Ave., just south of 62nd St.
Officials said the fire was considered at a 2 alarm level because of manpower.
2 alarm fire in Chicago Lawn neighborhood
A one-and-a-half story bungalow had a "total burnout," and it extended to a two-flat and another bungalow, fire officials said.
No one was living in the building where the fire started because it was being rehabbed, fire officials said.
Six people have been displaced and are now looking for a place to live.
Several dogs were also rescued from one of the occupied buildings that caught fire as a result of the initial blaze, including a puppy that was too small to stand on its own.
A firefighter was the only one with any injuries and they're expected to be okay.
No word on what started the fire.
The Sun-Times Media Wire contributed to this story.