What started out at as a small fire in a Harvey auto repair show turned into a blaze that sent three firefighters to the hospital.
Crews from five departments responded to the fire around 9:15 p.m., according to NBC Chicago.
Workers said the fire was accidental and they were unable to contain it.
Sixty firefighters responded to the scene as flames engulfed the structure and the roof collapsed.
The three firefighters were taken to Ingalls Memorial Hospital suffering smoke inhalation.