At approximately 1857 hours Engine Company 3 was alerted to mutual aid to St.Mary’s County for the reported RV fire. Engine 34, and Chief 3 quickly responded. Engine 34 arrived on location to find a working RV fire. As the crews from Solomons were quickly deploying 2 attack lines, the owner of the RV advised that his dog was still inside. The Solomons crew went to work quickly to locate the missing dog. The dog was located and lifesaving efforts were performed but were sadly unsuccessful. Engine 34’s crew had the fire under control within a few minutes of arriving. Crews from Bay District and Hollywood arrived and assisted crews on scene with cleanup and overhaul. Crews were on scene for about an hour before being released in service.