ST. LOUIS (AP) — St. Louis Zoo officials say they are working to find a way to keep an Andean bear named Ben inside his enclosure after he escaped Thursday for the second time this month.

The bear was outside for less than an hour and was found only about 100 feet away from his habitat, zoo officials said in a statement. The 4-year-old bear, who weighs about 300 pounds, was tranquilized and returned to the enclosure.

Visitors and zoo staff were kept inside zoo buildings during Ben’s escapade.

The bear escaped on Feb. 7 by tearing apart clips that were attached stainless steel mesh to the frame of the enclosure’s door. He did not wander far and was outside for about 90 minutes before being returned.

In response, the zoo added stainless steel clips with 450 pounds of tensile strength to the mesh. But Ben managed to snap those clips Thursday.

Zoo officials said they are working on alternative ways to secure the enclosure and will seek advice from the Association of Zoos & Aquariums Bear Taxon Advisory Group.