Galax firefighters are on the scene of a large fire on South Main Street.

Crews were called to the 200 block of South Main Street around 7 a.m. Friday, where a thick column of gray smoke billowed from the roof and upstairs apartment windows of the building. Fire soon broke through the roof and out the windows.

Firefighters believe the fire started upstairs but have not yet determined a cause. It was not immediately clear if there were any injuries in the blaze, but officials were able to account for most of the building's tenants.

The building also houses Altered Edge, a comic book and gaming store.