FERNDALE, Wash. -

Authorities say a woman set a fatal fire at a Ferndale house because she believed an ex-boyfriend had been staying there.

The man was not hurt in the New Year's Day fire, but firefighters found the body of a 23-year-old woman who died of smoke inhalation.

Whatcom County deputies arrested 52-year-old Katherine Sofie on Tuesday on suspicion of first-degree murder.

The Bellingham Herald reports it's unclear why the victim Mindy Rhoads was in the home. It was being scrapped in preparation for demolition.