Just before 2045 E18 was on scene of an automatic fire alarm at 9900 Greenbelt Rd. Upon arrival they found smoke in an adjoining building and requested to fill the box. Truck 28 arrived on scene and took the rear of the building. Crews found a fire in a barber shop with extension into the wall and surrounding furniture. Truck 28 operated on scene for just over 1 hour before heading home.