North Stonington _ A small building at 229 Grindstone Hill Road was damaged by fire early Sunday, according to Fire Marshal George P. Brennan.

The building, which is used as a guest quarters, was not occupied at the time. Somebody at the property used a garden hose to extinguish the blaze, and the fire was “basically out” by the time firefighters arrived and assisted with cleanup, Brennan said. Damage to the interior and contents is estimated at $10-$12,000, he said. The cause and origin of the fire are under investigation.