Members assisted Portsmouth, NH with a 4 Alarm Structure Fire at the Portsmouth Gaslight Company on Market St. The fire, in the downtown district, was reported by the crew of Tower 5 while they were conducting their Wednesday Fire Boat checks. A large amount of smoke was seen in the are of the downtown. Upon arrival they had fire on multiple floors in a vent system and chimney. The SMART Truck was dispatched on the 3rd Alarm assignment, and Truck 8 was sent to cover Portsmouth Station 1 on the 4th Alarm. After the fire was under control, Truck 8 was reassigned to do fire watch with Portsmouth Engine 4 at the scene.