(Silver Bay, MN)  --  The famous sea arch at Tettegouche State Park collapsed into Lake Superior over the weekend.  A naturalist made the discovery at the landmark that has been photographed hundreds of thousands of times.  Park Manager Phil Leversedge says what remains is now called a stack or seat stack, 15 or 20 feet from the main cliff.  He says weathering and erosion created a fracture and the arch succumbed to gravity. Park visitors now have a new feature they can take can pictures of along the North Shore.