PORTAGE, Wis. – An industrial fire at a central Wisconsin dairy plant caused ‘significant’ damage after it was started in a room storing butter, which then melted and spread throughout the building.

According to the Portage Fire Department, firefighters responded to Associated Milk Producers Inc. (AMPI) at 301 Brooks Street around 9:15 p.m. on Monday, January 2. Crews en route were told that both smoke and fire were visible from the outside of the building.

Upon arrival, Portage firefighters confirmed heavy smoke and fire from the roof of a multi-story commercial concrete structure. Crews extended hoses to the front entrance but were pushed back by the extreme heat and heavy smoke.

Unable to access the building, firefighters continued until additional agencies arrived.

Fire crews tried to gain access from each end of the building to control the fire spread. However, heavy smoke and runoff stopped crews again.

The fire reportedly started in a room where butter was being stored. As the butter was heated, it started to flow throughout the building, which increased the heat of the fire.

After several hours with multiple agencies responding, the fire was contained and put out before it could spread past the firewalls and throughout the building.

The Portage Hazmat Team was also called to the scene to contain the runoff into the storm sewers and into the canal. The crews placed boom and other absorbents to control the runoff.

There were no injuries reported, and officials are investigating the cause of the fire.

The Wisconsin Department of Natural Resources is expected to assess any damages to the drains and waterways from the butter runoff.

No additional information was provided.