The second oldest polar bear in captivity in North America - Snowball at the Cleveland Metroparks Zoo - was found dead unexpectedly Friday morning. Snowball was 37-years-old, and died after breakfast, having shown no signs of illness.

The zoo has already conducted an autopsy, but does not suspect foul play or injury. Polar bears typically live 15 to 18 years in the wild, and into their 30's in captivity. The oldest polar bear in capativity was 41 at her home zoon in Winnipeg, Canada.

Snowball was one of three polar bears at the Cleveland zoo, and was considered a queen amongst the trio. She was captured in the Canadian province of Manitoba as a baby, and brought to Cleveland in 1971. Over the years, she had many cubs to multiple fathers.