Updated

A third sea lion has died at Rochester's Seneca Park Zoo in western New York in just four months.

Zoo Director Larry Sorel confirmed Monday that Sunny, a sea lion pup born at Seneca Park in June, unexpectedly died last week for reasons that have not yet been determined.

Staff found Sunny at the bottom of her pool on the morning of Dec. 12. A necropsy showed no obvious cause of death.

Jeffrey Wyatt, the zoo's director of animal health and conservation, says evidence suggests no link between the three recent deaths.

Sunny's mother, Marina, died after suffering a seizure in September. Boomerang, a 10-year-old male sea lion, died of congestive heart failure in October.