COLUMBIA, S.C. — The Riverbanks Zoo says their oldest elephants passed died unexpectedly overnight. 

The zoo said Thursday that Robin, a 49-year-old African elephant, passed away. She was the eldest of two female elephants at Riverbanks.

"Robin had a lot of spunk and acted half her age," said John Davis, director of animal care and welfare at Riverbanks Zoo and Garden. "At 49, she lived well beyond her life expectancy because of the tremendous care she received throughout her life. We love her, and we will miss her."

The zoo's elephant exhibit will be closed Thursday. 

Staff say Robin appeared to be healthy.

"There were no signs of illness leading up to it. She was her bright and spunky self [Wednesday] and we did have a report in the middle of the night that she was up and about with Belle. Then apparently some time early this morning she laid down and unfortunately died," Davis said outside the exhibit Thursday afternoon.

Belle is the other elephant currently residing at Riverbanks.

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In June, it was announced that Robin and Belle would be leaving the zoo to find a new herd and to make room for a new rhino exhibit.

Davis said the training to prepare for the elephants to move did not cause issues with Robin's health.

"Whatever we exposed to them to training was all a very normal part of their day and it was all done that the animals dictate how fast we move and how we go. And if the animal chooses to not participate, which they rarely do, because they get paid with a lot of really great rewards and treat items and things like that. So, no, there's nothing that would have led to this based on other than just the fact Robin was 49-years-old," Davis said.

Belle, the other elephant, was with Robin throughout Wednesday night, according to zoo staff. They say keeping her happy and healthy leading up to the move will be their biggest priority.

"We're going to definitely pick up the pace on reaching out to Belle to make sure, monitoring her along the way and how she's doing. But, spending a lot more time with her, more enrichment items to make sure she's getting everything she needs," Davis continued.

The zoo still plans to move Belle this fall.

Robin came to Riverbanks in 2007 from Disney's Animal Kingdom.