A massive fire broke out early Friday at an industrial building in the Old Irving Park neighborhood on the Northwest Side.
A second alarm was called about 4:30 a.m. and a third alarm about a half-hour later, for the fire in the 3900 block of North Pulaski, according to the Chicago Fire Department. More than 100 firefighters were brought to the scene.
Flames shot through the roof, which collapsed, fire officials said. No one was inside the building.
One firefighter suffered a minor back injury, officials said. The fire was under control by 5:30 a.m.
The cause is under investigation.