An industrial fire at a central Wisconsin dairy plant caused “significant” damage after it sent butter spreading throughout the building and into a nearby canal on Monday. KTLA’s sister station WFRV reports.

According to the Portage Fire Department, firefighters responded to Associated Milk Producers Inc. shortly after 9 p.m. for smoke and fire visible from the outside of the building.

Upon arrival, Portage firefighters found heavy smoke and fire from the roof of the building. As crews worked to bring hoses in through the front entrance, authorities say they were pushed back by the extreme heat and heavy smoke.

Fire crews then tried to gain access from each end of the building to control the fire, which started in a room where butter was being stored. However, heavy smoke and butter runoff stopped crews again.

As the butter was heated, it started to flow throughout the building, which increased the heat of the fire and slowed fire crews even more.

Portage Fire Chief Troy Haase told local reporters that a layer of butter roughly 3 inches thick coated the steps to the building, slowing firefighters as they tried to enter the building. Butter coated the hose line, leaving crews unable to hold onto it any longer.

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 butter runoff into the storm sewers and into the Portage Canal. The crews placed boom and other absorbents to control the runoff, according to the fire department.

Butter could still be seen floating in the canal on Tuesday.

The cause of the fire remains under investigation and the Wisconsin Department of Natural Resources was working to assess any damages to the drains and waterways from the butter runoff.