An early-morning fire at the Wisconsin Precision Casting Corporation facility shut down several streets in Lake Geneva
The business was closed Sunday, so no one was injured.
Capt. Mark Moller-Gunderson, of the Lake Geneva Fire Department, said first responders swept the building twice to make sure it was empty.
"It's a large building. It was tough to work our way through it. There's a lot of machinery, a lot of pallets," he said.
He added a gas main broke, making the blaze more dangerous.
"We're not sure how it broke, but it was putting out a lot of flame," Moller-Gunderson said. "We had to cut off gas to the building."
Lt. Edward Gritzner, of the Lake Geneva Police Department, said a police officer on routine patrol spotted dark smoke emanating from the building just after 6:30 a.m. and called for help.
"It's not unusual for smoke to be coming from this building, but the officer noticed it was a darker smoke, which drew his attention," Gritzner said. "At that time, he pulled up closer to the building, approached a door, looked through that door, and noticed the building was filling with smoke."
Moller-Gunderson said fire crews were able to put the blaze out in about 45 minutes.
But they remained on scene for several hours ventilating the building.
"We had a crew on the roof, we had to bust all the windows out to release the smoke and heat and then peel back a membrane on the roof," Moller-Gunderson said.
He said mutual aid from fire departments in southern Wisconsin and Illinois assisted at the scene.
HAZMAT units from Racine and Walworth County were also brought in as a precaution.
"We didn't know what materials were inside," Moller-Gunderson said.
Moller-Gunderson said investigators continue to look into the cause and origin of the fire.
He didn't have an estimate on the cost of repairing the building, but said it sustained a lot of smoke and heat damage.