Great Bend ? Officials at a central Kansas zoo are trying to figure out how a 150-pound mountain lion escaped from its enclosure.

The 14-year-old female was shot and killed by police at the Great Bend Zoo on Sunday evening.

Zoo director Mike Cargill says the mountain lion escaped during feeding time, about 30 minutes before closing time. Visitors were still at the zoo, and Cargill says the animal had a tendency to be aggressive.

Cargill says the zoo would normally prefer to capture an escaped animal with tranquilizer darts. But it would have taken at least a half-hour for the darts to arrive, so police were called as the mountain lion moved among various exhibits.

Cargill said the big cat died instantly when police arrived and shot it.