Fire crews worked to quiet a fire at American Heat Treating in Dayton after heavy smoke was seen coming from the structure on Sunday afternoon.

Crews responded to Broadway Street and Nicholas Road at about 2 p.m. Nobody was inside the heat treating business at the time the fire started, according to fire officials. The fire appears to have started in a furnace, said District Fire Chief Lester Flohr.

“(It was) burning and operating in a faulty fashion,” he said. “We’re in the process of getting building and company representatives on the scene.”

Firefighters shut off gas to the structure. No formal damage estimates have been made available and no neighboring structures were harmed.

Flohr said the situation is stable.

“It won’t extend beyond the furnace and area in question,” he said on Sunday.