April 2007 cover of Vanity Fair. Photographed by Annie Leibovitz.

Knut is dead. The famous four-year-old polar bear cub who was rejected by his mother at birth, posed with Leo Dicaprio for Vanity Fair, starred in countless feel-good two minute news segments, and was once given an Italian girlfriend named Gianna (only to lose her again later)…died today, in his pool, in front of roughly 600 people.

According to the AP, hundreds of fans have already gathered at the Berlin Zoo to say their goodbyes before the empty bear enclosure.

“I can’t comprehend what happened there. He was happy before, there were no signs of anything — it’s so shocking,” said fan Eveline Litowski, who said she had come to the zoo to find out more about Knut’s early death.

Litowski was among those who crowded around Knut’s empty compound Sunday, laying down red roses and white stuffed polar bears, lighting candles or putting up pictures of Knut with personal messages for him. Many children had drawn pictures of Knut or written farewell poems for their beloved bear.

Sadly, and somewhat interestingly, Knut’s keeper (who stayed with him 24 hours a day, bottle feeding him every two hours when he was a small cub) died at only 44 years old. A heartattack while at home.

While no one yet knows what killed Knut. He was too young to die. I also think he was both too old and too young to be in a zoo. That is, I would love to live in a world in which polar bears could only be found in the circumpolar arctic. Polar bears notoriously don’t do well in zoos. When I first started looking into the use of psychopharm for captive animals, it was Prozac and polar bears that came up first. It is just too hard to meet the needs of a creature so large, so used to cold climes, and to ranging such vast distances, inside of a confined space. No matter how many plastic toys or food puzzles are tossed in. Yes they will breed in captivity (Knut is somewhat tragic evidence) but this doesn’t prove good mental welfare.

Polar bears entertaining themselves by investigating the bow of the submarine USS Honolulu when it surfaced 280 miles from the North Pole. The photo was taken by a Lookout from the bridge of the sub. According to him, the bears investigated the boat for almost 2 hours before leaving. Photo: Chief Yeoman Alphonso Braggs, US-Navy

Knut sucks the thumb of his keeper, Thomas Doerflein, in April, 2007 in Berlin. Photo: Life