Panic after tiger escapes and mauls man to death

San Francisco Zoo was under lockdown yesterday as staff tried to work out how a tiger escaped from its pen late on Christmas afternoon, killing one man and badly mauling two others before it was shot and killed by police as it charged them.

As word came of a tiger on the loose at about 5pm on Tuesday, an hour before the zoo shut for the night with only 20 visitors on the grounds police sped to the scene in semi-darkness, where they found a severely injured man in front of the enclosure where the tigers were kept. That man later died.

Aided by police helicopters with searchlights, four officers then found the tiger itself outside the zoo cafe 300 yards away, sitting beside another man covered in blood, and with deep bites and claw marks on his head, arms and hands. Another injured man was close by.

The zoo was swiftly evacuated amid initial, happily erroneous, reports that three of the four other tigers kept in the enclosure had also escaped. The surviving victims, both in their twenties were being treated in a local hospital, where their condition was described yesterday as "serious but stable". They were otherwise both in good health, "so I think they have a good chance", a hospital spokesman told ABC News.

But the questions were only beginning above all how the tiger had managed to escape from what was believed to be a secure enclosure, protected by a moat 20ft deep and 15ft across, and surrounded by a wall 20ft tall, and with just one locked access door. "There was no way out through the door," said Robert Jenkins, the zoo's director of animal care, "it must have leapt the moat, or otherwise climbed out."

The dead animal was a Siberian tiger named Tatiana, weighing 300lbs or 21 stone, one of 600 of the endangered species that live in captivity worldwide. She had arrived at San Francisco from Denver zoo several years ago, in the hope that she would mate.

Instead, Tatiana established a record of violence. A year ago, under the eyes of horrified visitors, the tiger mauled a zookeeper, seizing her by the hands and trying to drag her closer. That time, tragedy was averted as another keeper managed to break the tiger's grip, freeing his colleague.

"Nothing like this has ever happened before," a zoo spokesman said after that attack. Public feedings were suspended, and the security of the enclosure was strengthened, with the addition of special steel mesh and a new built-in feeding chute. The distance between the big cats and the public was also increased. Although a medical claim against the city by the injured keeper was dismissed, California state authorities subsequently fined the zoo $18,000 (9,000) for the assault.

Yesterday Gavin Newsom, San Francisco's Mayor, said that he was "deeply saddened" by what had happened and promised a full investigation "to uncover all of the facts and to understand how this tragedy could have occurred".

The zoo is open 365 days a year. Although no new visitors were admitted after 5pm on Tuesday, the grounds were not scheduled to close until an hour later. Employees and visitors were told to take shelter when zoo officials learnt of the attack.