AUGUSTA (AP) — Officials say the cause of the fire that killed three people in Unity may never be determined because there was little left of the mobile home that burned.

Investigators say they know the identities of two men and a woman who lived in the home — two men in their 50s and a woman in her 70s — but it’ll take work to confirm that they were the ones who died.

The fire apparently started Saturday night at the home at the end of a road but went unnoticed until the following morning when a passerby noticed the smoldering ruins. The damage to the bodies was so extensive that Maine Public Safety Department spokesman Steve McCausland said it could be a challenge to determine how they died.