Fire Chief Steve Thompson said the Brady family, two adults and four children, escaped unharmed from the Sunday night blaze, but one of their two pets died.
The animals were trapped on the second floor. Life Force Ambulance was able to revive one of the dogs who was unconscious at the scene but a second dog found later died, firefighters said.
The fire broke out at 11:44 p.m. There were no smoke detectors in the building, which is owned by David Cox of Atlantic. The building is insured but the tenants had no renters insurance, according to a fire report.
Firefighters from Hempfield and West Salem townships and East End in Mercer worked to put out the fire until about 4 a.m.
No one was injured.