Officials at the Cologne Zoo in Germany said a Siberian tiger escaped from its enclosure and mauled a keeper to death, before it was shot dead, UPI reported. A statement from the zoo said the zoo keeper, identified as Ruth K., failed to secure the gate to the tiger\'s enclosure after its daily cleaning. The tiger, Altai, was able to escape from its enclosure and attacked Ruth, biting her in the neck, Express.de reported. Ruth was taken to a hospital where she died from her injury. Zoo Director Theo Pagel shot and killed Altai before the animal attacked anyone else, the statement from the zoo said. \"This is the darkest day in my life,\" Pagel said. The zoo was temporarily shut down following the incident, though zoo officials said visitors were never in any danger.