PUVFD was activated at 5:45 pm this evening for a reported house fire on Snyder Avenue in the Hillside Estates Plan of our home fire district. Arriving firefighters found a working fire in a double wide modular home near the end of Snyder Avenue. Engine 36 arrived first and knocked down the fire in a short time but heavy smoke conditions caused a significant amount of damage throughout the residence. Firefighters spent some time overhauling the fire area checking for any fire extending into the walls and roof while ventilating smoke from the house. Also assisting were fire units from Marguerite, Dryridge, Trauger, Mutual, Calumet, Norvelt, Whitney-Hostetter and Latrobe VFD's while Youngstown VFD provided an engine to standby at our station until units cleared the scene. The cause of the fire was ruled accidental by human error and noted that no smoke detectors were operating at any time during the incident.