London Zoo’s beloved female tiger Melati was mauled to death Friday by her potential new mate when the tigers were being introduced for the first time. The two tigers had been kept in adjoining enclosures for 10 days in hopes that they would get used to one another, but their first interaction quickly escalated into aggression. Zoologists intended for the pair to breed as part of a tiger conservation program for the endangered Sumatran subspecies. The species are critically endangered, with just 400 left in the wild, making it vital that conservationists attempt to breed them. Zoo keepers intervened with loud noises, flares, and alarms when the interaction became aggressive, but were too late to save Melati. Zoo staff said they are “devastated by the loss of Melati, and we are heartbroken by this turn of events.”