Investigators say the only smoke detector they could find at the scene of a fatal fire in Hermon had its batteries removed.

One child died and another was in critical condition following Tuesday’s fire in a mobile home in the Penobscot County town.

The fire at 292 Wing Road in Hermon was reported at 7:15 a.m. The adult residents of the home, John Parker and Lasey Reidy, had left three children alone after getting up to do errands, according to the State Fire Marshal’s Office.

Wyatt Parker, 9, of Levant, died in the fire; his body was found in the living room. He had spent the night with his cousins Ashlyn Parker, 10, and John Parker, 8. Ashlyn was rescued from her bedroom by firefighters and was taken to Eastern Maine Medical Center for treatment for smoke inhalation. She was in critical condition when she was admitted to the hospital, but by Tuesday afternoon, officials said Ashlyn’s condition had improved.

John and Ashlyn are the children of Parker and Reidy. Wyatt was John Parker’s nephew.

Investigators believe the fire started in the kitchen but the cause remains under investigation.

A statement from State Fire Marshal’s Sgt. Tim York Wednesday said that first responders heard no smoke alarms going off when they arrived at the home and the only smoke detector investigators found had no batteries. Investigators were told there were two detectors in the house but only found one, he said.