Horn said he believes the fire started in the attic. He said the house sustained minimal damage and the blaze was brought under control within 30 minutes. Horn said Hagerstown Fire Marshal Tom Brown was investigating the fire's cause.
"We got a fire in the walls," Horn said. "It was a little hard to find. We found it with a thermal imaging camera."
Horn said after bringing the fire under control, firefighters continued to check for hot spots inside the house as a light drift of smoke billowed out the attic window.
Emergency crews shut off power to the house and Horn said a bedroom on the second floor was uninhabitable.
A neighbor across the street let the family rest inside his home. A young child inside the home, previously on oxygen for an unrelated illness, was examined by emergency crews and released to his father, an official from Community Rescue Service said.
Horn said no firefighters were injured though they needed to drink water to keep themselves hydrated as the heat and humidity rose.
Members of Washington County Emergency Services, the Community Rescue Service of Hagerstown, and the Long Meadow Volunteer Fire Company also responded to the scene.