SANFORD, Maine — The State Fire Marshal’s Office says three Sanford boys have been charged with arson in connection with the fire that destroyed the Stenton Trust Mill in Sanford on Friday.

The boys, a 12-year-old and two 13-year-olds, were arrested Sunday and taken to the Long Creek juvenile detention facility in South Portland early Monday morning.

[Video captures massive fire at vacant textile mill in Sanford]

Two men, who have been staying inside the building in recent weeks, were unaccounted for as of Monday morning, but those men have since been located.

Fire marshals will be assisted Monday by investigators from the Bureau of Alcohol, Tobacco, Firearms and Explosives, along with Maine State Police, Sanford police and the Sanford Fire Department.

Excavation equipment is being brought to the site to help stabilize the building.