WOOLWICH, Maine — Firefighters say a large fire on an island in coastal Maine took about 36 hours to extinguish.

The Woolwich Fire Department initially responded to reports of the fire around 2 p.m. Thursday. The fire was approximately four acres (1.6 hectares) large, and it threatened a cottage.

The cottage was saved after crews worked for hours to contain the fire.

The initial fire was contained Thursday night, but multiple fire crews worked through Friday to extinguish fires rekindled by underground pockets.

Woolwich Fire Chief Michael Demers says crews had trouble locating the fire at first due to widespread smoke. The Maine Forestry Service was called to assist and a helicopter was able to locate it.

The Forestry Service is still investigating the cause of the fire.