A spokesman for the zoo said that there were already a lot of giraffes with genes similar to Marius in the zoo's international breeding program, according to Time.
Many people attempted to save the animal — more than 20,000 signed an online petition, two zoos said they would take him, and an individual offered 500,000 euros to stop the killing, but the zoo anesthetized Marius then killed him with a bolt pistol.
Visitors, including families with children, were invited to watch while technicians performed an autopsy. The giraffe was skinned, dissected, broken down, and eventually fed to the zoo's lions.
Many organizations were disturbed by the highly publicized killing, with Animal Rights Sweden releasing a statement that Marius' death highlights what the group believes is a normal treatment for animals in zoos.
Rachel Zarrell is a news editor for BuzzFeed News and is based in New York.