A fire was intentionally set at a vacant school building in Pontiac early Monday morning, causing extensive damage and collapsing the second floor onto the first floor. No injuries were reported in the fire at Emerson Elementary School, located at 859 Emerson Avenue, in the city’s northeast corner. Firefighters and Oakland County Sheriff’s deputies were called to the scene shortly before 4 a.m. It’s believed the fire may have started on the second floor. A fire investigator from the sheriff’s office determined the cause of the fire to be arson.