A fan of late celebrity polar bear Knut places a candle during a demonstration outside the Zoo in Berlin, April 2, 2011. Knut, who won global fame as a cute cub, died suddenly in front of hundreds of horrified visitors on March 19 aged four after he fell unconscious into a pool at his enclosure. The polar bear suffered from viral encephalitis, an inflammation of the brain, which caused him to collapse before he drowned, a necropsy indicated. REUTERS/Fabrizio Bensch (GERMANY - Tags: ANIMALS)