Another set of twin polar bears has been born at The Columbus Zoo and Aquarium, shortly after one of the twins born last week to another bear died.
The central Ohio zoo says the latest cubs were born Monday to a bear named Aurora, about a week after her sister, Anana, gave birth.
Staff monitoring Anana's cubs through a camera in the private den noted Sunday that one of Anana's cubs had stopped moving. The cub died hours before the newest cubs were born. Zoo officials say they likely will never know why the cub died.
Zoo officials say polar bear cubs have about a 50 percent survival rate in the first few weeks.
The father of all the cubs is a 28-year-old bear named Nanuq.