GORHAM — An unoccupied single-family home on Great Falls Road (in photo) was destroyed Sunday morning.

State and local fire investigators spent Monday trying to determine who set three fires in Gorham.

The fires, which began March 27, have damaged or destroyed three vacant buildings: the Gorham SnoGoers clubhouse at 209 Mighty St. and two homes. Sgt. Joel Davis of the state Fire Marshal’s Office is leading a team of four investigators, who spent Monday canvassing neighborhoods, collecting evidence from the fire scenes and interviewing residents.

“We’ve been here all day and will probably be here for the rest of the week,” Davis said.

The public has been helpful, providing about a dozen tips, but there still were no suspects Monday, Davis said.

“We are asking people to be vigilant and if they notice something suspicious, call police. It could be something like a vehicle parked beside the road or a stranger walking through your neighborhood,” Davis said.

People can contact the Fire Marshal’s Office at 624-7076 or the Gorham Fire Department at 839-5581.