Colo, the first gorilla born in a zoo and the matriarch of the Columbus Zoo’s famous gorilla family died in her sleep overnight.

COLUMBUS, Ohio -- Colo, the first gorilla born in a zoo and the matriarch of the Columbus Zoo’s famous gorilla family, died in her sleep overnight, according to the zoo.

At 60 years of age she was the oldest gorilla on record and exceeded her normal life expectancy by more than two decades.

On Dec. 22, 2016 Colo celebrated her historic 60th birthday surrounded by thousands of fans and with birthday wishes coming from around the world.

“At the Columbus Zoo and Aquarium our mantra is to touch the heart to teach the mind,” said Tom Stalf, president and CEO. “Colo touched the hearts of generations of people who came to see her and those that cared for her over her long lifetime. She was an ambassador for gorillas and inspired people to learn more about the critically endangered species and motivated them to protect gorillas in their native habitat.”

History was made when Colo was born at the Columbus Zoo on December 22, 1956.

She was the first zoo-born gorilla in an era when little was known about conserving the western lowland gorilla but she had the support of a nation behind her. Her birth made headlines around the world.

Colo’s first keeper, a second-year veterinary student named Warren Thomas, was credited for both Colo’s birth and her survival. He defied orders from then-Zoo Director Earl Davis to keep Colo’s parents, Baron Macombo and Millie Christina, apart.

Despite Director Davis’ concerns that his prized gorillas would hurt each other if kept together, Thomas allowed them to spend time together, which resulted in the birth of Colo.

Thomas also found Colo, still in her amniotic sac, shortly after birth and provided mouth-to-mouth resuscitation to revive the lifeless baby. Thomas had a long zoo career including 16 years as the director of the Los Angeles Zoo.

The zoo said Colo’s gorilla and animal care family spent time with her body this morning.

Colo will be cremated and her ashes buried at an undisclosed location at the Columbus Zoo.

Prior to cremation, the zoo will conduct a complete postmortem examination to further define the cause of death. A malignant tumor was removed from under her arm on Dec. 3, 2016. At that time surgeons felt they obtained clean, wide margins when they removed the mass and until a necropsy (animal autopsy) is performed it is unknown if the cancer contributed to her death. The zoo says blood and tissue samples will also be collected to benefit the world zoo community’s efforts to learn more about this endangered species. Results of the necropsy are expected in approximately four weeks.

“She was the coolest animal I’ve ever worked with and caring for her was the highlight of my career,” said assistant curator Audra Meinelt. “It was not just about what she meant for the gorilla community but for whom she was as a gorilla. I’m heartbroken but also grateful for the 19 years I had with Colo.”