MENDHAM TOWNSHIP — Authorities say a fire that gutted a historic mansion on a Colonial-era farm in New Jersey earlier this year was intentionally set.

Morris County prosecutors say the Feb. 24 fire on the Pitney Farm property in Mendham Township was "caused by a human act" and is being investigated as an arson.

But further details on the investigation were not disclosed.

The unoccupied 11,800-square-foot mansion was inhabited by 11 generations of the Pitney family from 1722 until 2013, according to the Friends of Pitney Farm website. The property and the surrounding 12 acres were purchased by Mendham Township in 2009 and the group was working on a plan to redevelop a portion of the property.

Furniture and other valuables had already been removed from the uninhabited building before the fire occurred.

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