Georgia Aquarium employees first noticed just before Thanksgiving that Marina was ill, as she lost her appetite and has become disoriented.

She had been kept under 24-hour medical watch by aquarium staff and veterinarians, with almost 100 people involved in covering shifts to ensure her safety.

But on Friday night, Marina’s lost sense of direction became increasingly apparent, prompting additional people to aid in guiding her.

At the time of her death shortly after 2 a.m., 16 staff members and volunteers were in the pool with her until she stopped swimming and breathing.

Marina was transferred with other two whales from Wildlife Conservation Society’s New York Aquarium to the Georgia Aquarium in November 2005.

"We have to accept the whole life cycle here as biologists and our public does, too — while you have all these births you also have deaths," Jeff Swanagan, president and executive director, Georgia Aquarium, said. "It's part of the living collection. It's hard on us."

Also the Georgia aquarium officials said an autopsy will be performed in order to discover the cause of death.

The three other beluga whales at the Georgia Aquarium, Nico, Maris and Natasha, are all eating normally and responding to the husbandry team, Georgia Aquarium announced.