The Greater Vancouver Zoo said it is in “complete shock” after discovering a two-year-old Siberian tiger dead Wednesday morning.

The animal, named Hani, appeared healthy but lost her appetite for a day before she died, according to the zoo.

Her keepers also recently noticed lethargic and unusual behaviour in the tiger.

“All staff and volunteers at the zoo are devastated by Hani’s sudden passing,” the zoo said in a statement. “We are hopeful that the full necropsy that will be performed later today will provide some answers.”

Hani was born at the zoo’s sister facility, the Seoul Zoo in South Korea, in 2011 and was going to turn three on May 22.

The animal’s death came four months after the Greater Vancouver Zoo was forced to euthanize its oldest tiger, Sweetie, due to ongoing health issues.

Sweetie was 18 years old when she was put down on New Year’s Eve 2013. Siberian tigers live an average of about 10 to 15 years in the wild.

As few as 3,200 tigers exist in the wild today and all species are considered endangered, according to the World Wildlife Fund.