Updated: 6:40 p.m. | Posted: 3:15 p.m.
The Minnesota Zoo has taken its trio of brown bears out of public view after one of the grizzlies broke part of a glass barrier with a rock.
Animal Collection Manager Tony Fisher said the zoo had cleared the Grizzly Coast exhibit of objects the bears could carry, but one of them may have dug a basketball sized rock out of the ground.
Shortly after they went on display at 9 a.m. Monday, one of the bears bashed it against a pane of security glass.
Robin Ficker, who was visiting from Maryland, saw the bear grab the rock.
"The three bears, they were cavorting in the pool and wrestling and fighting," Flicker said, "and then all of the sudden one of these huge half ton bears picked up a very large rock — I would say it was at least 50 pounds — and did a chest pass, just like Wes Unseld used to to do, right into the glass."
Ficker wondered if the barrier would hold.
"The bear, I would say, was about 3 feet from the glass. It was just a short distance. But it was a very strong bear and a very large rock. And the first time he threw it, it cracked. And then he kept throwing it. I thought those bears are coming out of here," Ficker said.
Animal Collection Manager Tony Fisher said it broke only one of five glass layers, and visitors and bears remained safely separated.
"You know, they just like destroying things," he said of the bears. "They're always busy on our exhibit doing something, digging. We have trout in our pool for them to fish for, and that keeps them busy for quite a while, fishing for trout. But this morning he got a hold of a rock, which was not good."
Fisher said the zoo will build a temporary barrier to secure the bears until the glass can be replaced.
"We'll probably install another barrier in front of that glass panel ... that is bear proof," he said. "But it will just be in front of the broken glass so that we can get the bears back on exhibit and get people back enjoying the bears once again for the summer."
Fisher said it could be fall before the custom-made glass is replaced.
Monica Lake, capital projects manager for the Woodland Park Zoo in Seattle, said zoo exhibits are designed to withstand the strength and traits of each animal.
She said despite the scare, the design of Grizzly Coast seemed to work well.
"It did exactly what it was intended to do," Lake said. "The animals are still safe. The visitors are safe. And you know it was an anomaly. The exhibit has been open for many years."