One of the Assiniboine Park Zoo’s Amur tigers died after a fight with one of the other tigers Thursday morning.

The zoo said staff are “devastated” after the adult male tiger Baikal managed to get through an unlocked gate and into a transfer corridor connecting his enclosure to a new one containing two young males, Samkha and Vasili.

“This resulted in a confrontation between Baikal and Vasili, one of the young tigers, that ultimately resulted in Baikal’s death. This involved an internal gate between enclosures and at no time were Zoo visitors in any danger,” said the Assiniboine Park Zoo in a statement.

“Baikal had lived at the Assiniboine Park Zoo for over five years and this is a heartbreaking loss for our staff and our visitors,” Dr. Brian Joseph, director of zoological operations for the zoo, said in a news release.

The zoo is reviewing the incident and say they will take steps to prevent incidents like this in the future.

Baikal was one of four Amur tigers at the zoo. The others are Kendra, an adult female, and Samkha and Vasili, two-year-old brothers which arrived from the Calgary Zoo in January.

Robert Burnett said his son was watching Baikal, moments before the attack. Burnett said they saw Baikal walk past and enter a gated walkway. Burnett said they later heard a commotion but did not see the actual attack.