A gas line leading to an old furnace in a building on Second Street in The Dalles that houses a number of businesses was accidentally cut during demolition work Wednesday afternoon.  Northwest Natural along with Mid-Columbia Fire and Rescue and Dallesport Fire crews responded.  MCFR indicated on its Facebook page that a highly flammable amount of gas was present inside the building.  Windows in the upper level were either opened or broken to vent the gas out of the building.  Second Street was shut down for about one hour.