WINDHAM — The Maine fire marshal’s office is investigating an early-morning fire Sunday in a Windham apartment building that left one man dead and his fiancee in the hospital.

Firefighters pulled Parker Blanchard, 25, out of his bedroom and tried to resuscitate him outside the burning home at 13 Main St. but were unsuccessful, according to Stephen McCausland, spokesman for Maine Department of Public Safety. Annette Kowalic, 25, managed to flee the apartment and was taken to Maine Medical Center in Portland for treatment of smoke inhalation.

The fire was spotted at 3:37 a.m. by a passerby. All other occupants of the three-unit apartment building were able to escape the building, which was equipped with working smoke detectors, McCausland said.

“The fire marshals are working on a cause,” he said Sunday afternoon. “They need to tighten up a couple aspects of the investigation today or tomorrow. There’s no indication it’s anything but an accident.”

Sgt. Tim York of the Maine fire marshal’s office said that the American Red Cross was at the scene Sunday morning as well as investigators from his office.

Windham and Gorham fire departments worked to put out the fire, York said, adding that other agencies also may have been involved.