A fire broke out about 10:20 a.m. Thursday at an apartment at 707 E. Mercer Street in Harrisville.
The structure was fully involved when firefighters arrived on the scene.
The origin of the blaze remains to be determined, Harrisville fire chief Steve Bickle said.
A lack of fire hydrants required the attention of several nearby departments, including Clintonville, West Sunbury and others, Bickle said.
Nobody was injured in the fire.