SAN FRANCISCO - A Siberian tiger escaped from her cage yesterday, killing a visitor and mauling two others at the San Francisco Zoo.

Police shot and killed the tiger, named Tatiana, outside the zoo's Terrace Cafe shortly after the park closed to visitors at 5 p.m. She apparently had escaped from her fortified grotto by jumping the moat and over the fence and immediately attacked and killed a man in his early 20s.

She then headed for the zoo's Terrace Cafe, 60 yards away from the enclosure, and attacked two visitors, critically injuring them, said Robert Jenkins, the zoo's director of animal care and conservation.

Police encountered the tiger outside the cafe as she was mauling one of the victims, who was covered in blood, said Sgt. Steve Mannina of the San Francisco police. When officers tried to intervene, the tiger turned and headed toward them, and several officers fired numerous shots at the tiger.

Officials did not identify the victims, but KCBS radio reported that the tiger attacked two brothers, ages 18 and 19, and killed a 23-year-old man who was their friend. The brothers were taken to San Francisco General Hospital with critical injuries.

According to the zoo's Web site, Tatiana shared an outdoor enclosure with the zoo's second Siberian tiger, Tony, near the Lion House. It also has three Sumatran tigers at the west end of the Lion House.

The attack occurred about a year after Tatiana, who weighs 350 pounds, attacked and seriously injured a keeper's arm during a regular afternoon feeding.

The California Division of Occupation Safety and Health later ruled the zoo was responsible for that incident because of poor training and the way the tiger cages were set up.