Patty Peters, vice president of community relations at the Columbus Zoo & Aquarium, said Coco's death was unexpected. She said he ate all the food that was left for him Tuesday night but was down when employees arrived Wednesday morning.
Coco, who weighed 5 1/2 tons, was born in the wild in Borneo and was believed to be about 40 years old. His death leaves the zoo with two female elephants and two younger males, both Coco's sons.
"When I came to the Columbus Zoo in 1978, I was awestruck by the sight of Coco," Director Emeritus Jack Hanna said in a statement. "He invoked a sense of wonder in everyone who saw him, leading them to want to know more about elephants and to care about their plight in the wild. Coco will be missed."
Peters said employees spent 8 hours trying to save Coco. Firefighters used heavy equipment to try to get him back on his feet.