COAL VALLEY, IL - The two wolves escaped from the Niabi Zoo last week by breaking through a weak area in a chain-link fence. That's according to an investigation by the US Department of Agriculture.
Zoo officials say the weak part of the fence was underground and impossible for them to detect until the wolves dug into the dirt and got out.
But USDA officials still aren't sure how the female wolf got off zoo property. She had to be put down in a ravine in Coal Valley two days after she escaped.
Niabi officials have hired an outside fencing company to check the zoo's perimeter.
The wolf exhibit is closed for now, but the zoo director says a bigger wolf pen will eventually be built in its place.