The cause of a fire at Garvin Scrap Metal on Friday is unknown.

WINFIELD TWP — Firefighters said they don’t know what caused a Friday morning fire at Garvin Scrap Metal.

The fire, reported just before 11 a.m., ignited tires that produced clouds of black smoke that were visible for at least a mile away.

Saxonburg Volunteer Fire Department Chief Christopher Dean said an employee saw the fire and called 911.

He said no one was working in the scrap yard when the fire started, and no one was injured.

The Herman and Buffalo Township volunteer fire departments and county hazardous materials team also responded to the fire.