The popular ice caves on Lake Superior near the Apostle Islands are now closed, concluding an unprecedented number of sightseers.  The National Park Service says the caves along Lake Superior were closed just hours after midnight Monday.  The park service says the ice was getting too weak to support foot traffic to the caves.  138,000 people visited the caves this winter.  That figure dwarfs the 12,700 people who visited in 2009, the last time the lake froze enough to make the caves reachable by foot.

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