It took 22 firefighters nearly an hour to control a fire that destroyed a two-story, wood-frame house in Charles County on Sunday afternoon.

The occupants, Anna Maus, 44, and her son Damian, 19, were uninjured in the blaze, which started shortly before 5 p.m. at 2010 English Oak Ct. in Waldorf, according to a report from the state fire marshal. The fire, which originated in the living room, spread throughout the house, causing $250,000 in damage, the fire marshal's office said.

Deputy Fire Marshal Chuck Damman said the cause of the fire had not been determined, but it appeared "suspicious in nature and [remains] under investigation." It was unclear whether the home's smoke detector was working.

Anna Maus had just finished cooking and stepped outside the house where her son was cleaning the family's swimming pool. Within five minutes, the two told investigators, they heard a loud noise from inside. Damian Maus went back inside the house and saw fire and smoke in the kitchen and living room. A neighbor called 911 to report the fire, and units responded from Waldorf, Brandywine, Baden and Clinton. Residents of an efficiency apartment on the premises were not home when the fire occurred, Damman said.