A Rehoboth Beach home was significantly damaged Monday night after a heavy fire tore through the property, according to the State Fire Marshal’s Office. Investigators estimated about $300,000 in damages for the home, Chief Deputy State Fire Marshal Harry Miller said. The fire started in the first-floor utility room, when an electrical malfunction of branch circuit wiring sparked the blaze, he said. Firefighters from multiple departments were called at about 11:54 p.m. to the 500 block of Bayard Ave. in downtown Rehoboth Beach for a fire, Miller said.