Tiger kills 1 visitor at US zoo

A female Siberian tiger escaped from its enclosure in a San Francisco zoo on Christmas day and attacked three visitors.

A Siberian tiger in a file photo. Authorities continued on Wednesday to search the San Francisco Zoo for clues to how a tiger escaped from its enclosure on Christmas Day, killing one visitor and leaving two others seriously injured. (Xinhua/Reuters Photo)

One was killed at the scene and the other two were injured.

The two survivors have been taken to a local hospital and are in stable condition.

They are being treated for deep bites and claw cuts on their heads, necks, arms and hands.

The tiger was shot dead by police. The zoo has been closed as investigators are trying to determine how the tiger escaped.

The tiger, a female named Tatiana, was the same animal that ripped the flesh off a zookeeper's arm just before Christmas in 2006.