WINDHAM, Maine (AP) — A 9-year-old boy is being treated for serious injuries after falling about 20 feet while collecting icicles from the roof of a Maine apartment building.

The boy was unconscious when emergency responders arrived at the apartment in Windham on Thursday.

The boy’s grandmother told police that he was out searching for icicles when she heard a noise outside. She went out to discover him on the ground in a narrow gap between two apartments.

Windham police Sgt. Peter Fulton tells the Portland Press Herald it’s unclear how the boy got on the roof, but he could have climbed the fire escape or gone through a third-story window.