Updated

Minnesota Zoo officials are investigating how a Mexican wolf escaped from its enclosure, prompting zoo staff to fatally shoot the animal.

Zoo spokeswoman Kelly Lessard says the wolf got out of the Northern Trail exhibit and into a bison area at the zoo Wednesday in the Minneapolis suburb of Apple Valley.

She says the area was evacuated and the wolf was shot because it was considered a threat. No people were hurt and the wolf never left zoo grounds.

Zoo visitor Mary Woestehoff of Richfield says she saw the wolf running on a path, prompting her to scoop up her 18-month-old daughter. She says she used a nearby emergency phone to report the loose wolf.

The animal was a Mexican gray wolf, which is on the federal endangered species list.