The Brown County Sheriff's Department officially declared the September 5 fire at the old Lincoln School building was an act of arson.
The fire destroyed the abandoned building located at the intersection of Old Martin and Ryan Roads in the Town of Rockland.
Watch: Old school goes up in flames:
In a news release, deputies say the building had no electrical or heat sources before the fire started. When firefighters arrived to the scene at 2:15 AM on September 5, they found the building fully engulfed. The investigation into who started is on going.