Firefighters were called out to ThyssenKrupp Waupaca Plant 1 at 11:20 a.m. Monday, Aug. 30.
Waupaca Fire Chief Jeff Olson said the fire was caused by a hydraulic line blowing out, which caused oil to sink into the insulation on the ducts at the foundry. Heat from the melting operation then sparked flames in the ductwork.
Employees were evacuated as smoke came out the building.
“The foundry had their emergency resopnse team in action when we got there,” Olson said.
He said firefighters pulled out insulation to control the fire.
“We couldn’t use water in there because if you put water on molten iron it causes it to explode,” Olsen said.
Waupaca firefighters were at the scene for about two hours.