At 1150 hrs Solomons was alerted to a 1st due fire at the Navy Rec Center. Engine 31 first arrived and pulled up to a 25x30 bath house with fire thru the roof on the Bravo/Charlie side. Engine 31's crew advanced a crosslay to the building to find the ceiling of plywood involved. Multiple units from surrounding company's opened up with chainsaws inside the structure to assist in knocking the fire. Crews operated for about two hours before returning to service.