Grizzly bear uses rock to shatter glass pane of enclosure at Minnesota Zoo

APPLE VALLEY, MN (KTRK) -- A grizzly bear at the Minnesota Zoo used a 50-pound rock to shatter a glass barrier, cracking part of its enclosure.

Director of Animal Collections, Tony Fisher, told WCCO-TV that the bears weren't being aggressive or trying to escape. They were just playing with giant rocks.

The zoo had anchored everything down in the Grizzly Coast exhibit, but one of the bears was able to dig the large rock out of the ground. Zoo officials don't know for sure which of the three grizzlies picked up the rock, but they believe it was Kenai, a middle-size brown bear. The zoo says on its website that he likes to wrestle and play with new objects.

Fisher says nothing like this has happeend since the three orphaned bears arrived from Alaska in 2008.

"Everything else in this exhibit is pretty much concrete and steel, pretty indestructible," Fisher said. "We designed this exhibit to withstand the bears, and what they can do."

The exhibit is now closed until a replacement pane can be installed.