OAKLAND (CBS SF) — Oakland Zoo workers were in mourning Wednesday after a long-time visitor’s favorite M’Dunda, the African elephant, collapsed and died inside the facility’s elephant habitat.

Dr. Joel Parrott, President & CEO of Oakland Zoo, said M’Dunda had formed a strong bond with his staff.

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“M’Dunda has been part of our Oakland Zoo family for 26 years,” he said. “She was such a gentle being, and closely bonded with her keepers. We’ll miss her greatly,”

Zookeepers found M’Dunda collapsed on Tuesday afternoon and immediately cleared other elephants from the habitat so they could safely enter and provide aid with the Zoo’s two veterinarians and supporting veterinary technicians.

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Parrott, who is also a wildlife veterinarian, also rushed to the scene to aid her. Upon approaching her, however, it was clear she was already deceased.

M’Dunda celebrated her 50th birthday in September with a party attended by zoo workers and visitors.

She came to Oakland Zoo in 1993 from San Diego Zoo, and quickly built a reputation of having a very gentle and kind demeanor. She rumbled to communicate with her herd mates and keepers, and was often observed trunk twirling with Osh, the male of the herd.

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M’Dunda’s body was transported Tuesday evening the UC Davis School of Veterinary Medicine for a necropsy and testing to determine the specific cause of death.