When fire crews arrived around 4:15 a.m., the flames were through the roof of Horizon Metals, located at 3925 North Pulaski Road. There was also a large explosion - possibly a propane tank - forcing firefighters into defensive mode.
A second alarm was called about 15 minutes later, bringing more than 100 firefighters to the scene. A third alarm was called about 15 minutes after that. The roof eventually collapsed.
The blaze was under control by 5:30 a.m., before the flames spread to a nearby house. It was extinguished less than an hour later. Firefighters stayed at the scene to watch for hot spots. The building is a complete loss, authorities said.
The metal plating business was closed when the fire started. No one was inside the building, officials said.
A hazardous materials team was called to the scene as a precaution. Authorities later said there was no threat.
One firefighter suffered back injuries while battling the blaze. He was transported to Swedish Covenant Hospital for treatment and is expected to be OK.
Irving Park Road was closed from Pulaski to the Kennedy. Pulaski was closed from the Kennedy to Irving Park. The Kennedy exit ramp to Pulaski was also closed, so drivers were forced to exit at Kostner or Addison instead.
CTA No. 53 and No. 80 buses were temporarily rerouted due to street blockage.
The cause of the fire is under investigation.