The roof of Schomberg’s Aerospace Metal Finishing plant collapsed Monday morning, as firefighters battle the blaze which is emitting black smoke and multiple toxins into the air.

The fire broke out early Monday morning at the building on Proctor Road, on the east side of Hwy. 27, south of Hwy. 9, near the Trisan Centre recreation complex.

A hazardous materials team is at the scene, along with firefighters and police.

OPP officers have closed Hwy. 9 from Leonard Road to Hwy. 27.

King Township spokesperson Jason Ballantyne said the town evacuated the immediate area as a precaution, explaining fire started in the building’s mezzanine, and no one was hurt.

“It’s defensive now,” he said. “No one is in the building, but we have 45 firefighters on scene.”

The only chemical he could confirm that was burning was sulphuric acid.