The San Francisco Zoo and its visitors are mourning the death of its silverback gorilla.
The Zoo says the gorilla, Oscar Jonesy, died suddenly after a medical procedure.
Oscar had been at the San Francisco Zoo since 2004. He was loved by staff and visitors.
At 43, he was the third-oldest male of his species living in a United States zoo.
After the zoo announced the death of its beloved western lowland gorilla, reaction poured in on social media from visitors commenting he was the highlight of their trips. One person wrote Oscar's wise eyes were a reflection of his soul.
In a statement, the zoo's CEO and executive director said "We are heartbroken by the loss of Oscar. He was truly an amazing ambassador for this critically endangered species and a favorite among staff, guests and volunteers alike."
Oscar underwent a medical procedure Thursday afternoon. The chief veterinarian said the procedure went well and he was being monitored during recovery from anethesia by a vet. That is when Oscar suddenly became unresponsive and stopped breathing.
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The veterinary team was unable to revive him.
The zoo said there were no signs of serious illness found during the examination, but a necropsy exam at University of California, Davis could give them more answers soon.
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Jenessa Gjeltema, an associate professor of clinical zoological medicine at UC Davis, said gorillas can live about 30 to 40 years old. But in a zoo and receiving healthcare, gorillas can sometimes live up to 50 years old.
"I would consider a gorilla of 43 years to be an elderly animal and I would consider them to be at increased risk for a potential complication under anesthesia. A lot of that depends on individual health," Gjeltema said.
The San Francisco Zoo did not specify what kind of medical procedure the gorilla underwent, but Gjeltema said if there was a health condition that needed to be treated, discussion with the caretaking team and everyone involved is essential.
"The risks of intervening and not intervening both have to be weighed carefully," Gjeltema said. "A lot of these elderly animals can have underlying health conditions that are risky if you don't treat them and don't intervene to do a procedure."
The zoo said it is giving the female gorillas an opportunity to mourn Oscar's death and will be monitored.
