Knut the beloved polar bear died on March 19th and heartbreaking new video has surfaced of Knut's final moments.
The world's most famous polar bear was walking in circles, disoriented and appearing to suffer a seizure. It was clear something was terribly wrong.
Visitors watched in horror as Knut stumbled sideways and suddenly fell into the pool. He thrashed around for a few seconds and then was still. Knut was dead.
"It certainly appeared like it was a very sudden and traumatic episode. Polar bears can live into their mid to late 30s even. Certainly four years old is way too young, it's very suspicious," says Geoff Hall, General Curator of the Cleveland Metroparks Zoo.
Knut shot to worldwide fame as a tiny cub. Rejected by his mother, the adorable cub was raised by a zookeeper, who handfed him with a baby's bottle.
He captured the hearts of millions around the world and even appeared with Leonardo DiCaprio on the cover of Vanity Fair.
Today Knut's fans around the world are in mourning. One fan wrote in an online condolence book:
"I am in complete despair. Every visit to the zoo brought happiness, because he was such a warm-hearted animal."
Knut was just four years old.
Tests are being conducted to find out why Knut died so young.