(Editor's note: Update available here.)
"Our guys are out now trying to make the arrests," he said.
Two of the teens lived on Ellis Street, near the Mill, and one was from Hiram and one from Lithia Springs, Miller said.
The Sheriff expects to have a news conference sometime this afternoon.
The structure, which dated back to 1897, smoldered for several days and authorities tried to keep photographers and on-lookers away from the area.
The building had been abandoned and in derelict condition for many years, with the property surrounding the mill grown up with vegetation. Nothing was stored in the building.
Because of the dilapidated condition of the building, and the presence of numerous old timbers with creosote (high flammability), the Fire Department decided to allow the engulfed structure to burn itself out, and proceeded to protect surrounding properties, none of which was ever in danger.
There were no injuries at the fire scene.
The mill faces Bankhead Highway and the parallel Norfolk Southern Railway, and both were shut down due to smoke and fire embers blowing northward.
The Douglas County Fire/EMS investigator stated that the fire looked “suspicious” because there was no electrical power in the mill and no external fire sources, such as lightning, in the area at the time the fire started.