The aim was a noble one: Bring the male Sumatran tiger Asim from Denmark to the London Zoo to mate with a female named Melati as part of an effort to increase the endangered species' population. What happened instead left the zoo heartbroken: The two were brought together for the first time Friday, and the introduction ended with Melati's death. The zoo explained in a statement that for a period of 10 days, the tigers were kept in adjoining enclosures, where they were able to "see, smell and react to each other."
After detecting "obvious positive signs," the decision was made to allow them to meet, with the hope being that they would eventually mate. Things started off typically, but Asim quickly turned aggressive. The zoo's countermeasures, which included the use of loud noises, flares, and alarms, weren't enough to keep Asim from "overpower[ing]" Melati, who was declared dead. USA Today reports that of existing tiger subspecies, the Sumatran tiger's population is the smallest, at 400 by the World Wildlife Fund's count. The AP cites Tigers in Crisis' slightly larger count of 500 to 600 Sumatran tigers in existence. (Read more Sumatran tiger stories.)