Heiner Kloes, in charge of bears at the zoo, said they were still trying to determine why the beloved four-year-old animal passed away. Knut collapsed and was found dead in a pool of water. He was the first polar bear to be born in captivity in the zoo for 30 years and the first public appearance of "Cute Knut" in March 2007 attracted 100 camera crews from around the world. He generated millions of euros for the Berlin Zoo in lucrative merchandising and extra entrance fees.
Knut weighed nine kilogrammes (19-pound) at birth and triggered a wave of media coverage after an animal activist said he should have been put down after he and his brother, who later died, were rejected by their mother following their birth in December 2006.
Knut was reared by the zoo, with his keeper Thomas Dörflein bottle-feeding him and strumming Elvis Presley songs for him on his guitar. Dörflein died at age 44 of a heart attack in 2008.
Later in Knut's life, he shared his zoo enclosure with his mother, Tosca, and two other females, Nancy and Katjuscha.
But hopes that Knut might form a romantic attachment with one of the females were dashed as stories emerged of violent maulings.
One video posted online showed Katjuscha hurling herself at Knut's throat, in an apparent attempt to bite him, before tipping him into the water. SOURCE: The Local