From Roanoke County Fire & Rescue: Roanoke County Fire & Rescue crews were dispatched to the 4000 block of Koppers Road at about 1 a.m. for a reported structure fire at an industrial plant. When the first firefighters arrived, they reported a structure fully involved. Career and volunteer crews from the Fort Lewis, Masons Cove, Hollins, and Cave Spring stations responded and had the fire knocked down in about 20 minutes. Fire crews were able to contain the flames to the building where the fire originated. Fire investigators determined the fire to be accidental and sparked as a result of a welder conducting maintenance on machinery when an airline malfunctioned causing the flames to spread to nearby combustibles and engulfing the structure. Damage estimates are figured to be $500,000. The welder suffered minor burns while trying to extinguish the flames.