Knut was the orphaned polar bear cub raised in captivity that stole everyone's heart. Knut passed away in March at the age of 4 in Berlin when he suffered an illness; encephalitis. The latest polar bear cub, "Siku" to be born in captivity was orphaned by his mother, so he is being raised by hand in a Denmark Wildlife Preserve. He is only 5 weeks old and seems to be enjoying all the attention he's receiving. It's hard not to fall in love with this little guy.