Firefighter injured in extra-alarm fire at factory on Chicago’s North Side

CHICAGO -- One firefighter was injured after a large fire gutted a factory on the city's North Side Friday morning.

The fire started around 4 a.m. at Horizon Metals, located at 3925 N Pulaski, just north of the Kennedy Expressway.

The fire caused a propane tank to explode inside the factory.

The roof of the factory collapsed. The Chicago Fire Department experienced hydrant issues and had to bring hoses through the house next door to get more water.

One firefighter suffered a back injury and was transported to the hospital.

A WGN producer captured the fire with his cellphone while driving to work on the Kennedy Expressway

The fire has been struck, but the building is a total loss.

No word yet on a cause of the fire.

This is a developing story. Check back for details.