The Alaska Zoo's 19-year-old polar bear Lyutyik died late on Sunday, according to the Alaska Zoo's Facebook page.

The polar bear has been at the zoo since 2006.

It is with heavy, broken hearts that our Alaska Zoo team announces the death of Lyutyik. Affectionately known as “Lyu”... Posted by The Alaska Zoo on Monday, October 14, 2019

In an emailed statement, the Alaska Zoo said that "Lyu" or "Louie," as the bear is known, began to

The zoo performed blood tests, which indicated mild changes in liver function and a possible infection. Veterinarians used a course of antibiotics.

They also performed abdominal ultrasounds, but admitted that "due to Lyu's size, it was not possible to evaluated the entire abdomen," and after his death, they found a mass around one of his kidneys.

According to the Alaska Department of Fish and Game, the average lifespan of wild polar bears is 25 years.

"The Alaska Zoo offers its sincerest thanks to all of Lyu’s caretakers over the last 13 years, the friends and visitors who came to keep him company and all those who checked in on him via the live polar bear cam. We know you loved Lyu just as we did, and we thank you for that," they wrote in the statement.

They say that a public celebration of life will be announced soon.

Lyutyik (Photo courtesy of John Gomes)