The fire in a three-level townhome at 9936 Brookridge Court was in the middle of a row of residences, says Montgomery County Fire and Rescue Services spokesman Pete Piringer.

Investigators believe the fire began in a couch on the first floor in the living room. While smoke alarms sounded, fire officials say the townhouse was unoccupied at the time of fire.

Firefighters arrived to find heavy flames on the first floor, and smoke on the second level. Neighbors in nearby units were evacuated.