Plymouth, Wis (WHBL)  Firefighters in the city of Plymouth pulled a dog from the mill pond off of north Street this morning.  Deputy Police Chief Chris Ringle said a passerby apparently spotted the Black Lab which had broken through the ice in the mill pond which is part of the Mullet River.  Firefighters then got to the dog by placing their extension ladders on the ice.  The dog was pulled to safety and reported to be doing fine.