For decades, Colchester Zoo has been at the heart of families across Essex, with children frequently growing up alongside their favourite animal.
As a result, when news breaks that an animal in the park has died, it may frequently feel like the death of a cherished pet.
This year, the zoo reported that its last lioness, Naja, had died after being euthanised after a brief illness.
But her death isn't the only one that has broken Colchester's hearts.
We've gathered some of the most recent painful stories of much-loved animals who died at the zoo.
Billy-Joe the Chimpanzee
One of Colchester Zoo's longest-serving residents, Billy-Joe, died on March 1, 2018, after her caretaker discovered few treatments available to help her health.
When Billy-Joe first arrived at Colchester Zoo in the late 1970s, she was just six years old and displayed unique personality traits that endeared her to employees and visitors.
Unfortunately, it was later discovered that the chimp had deep vein thrombosis with a blood clot limiting blood circulation to her foot.
After numerous attempts to assist her, it was determined that few treatments were available that might aid her health, and the choice was made to put her to sleep.
Yatsey the Eurasion Griffon Vulture
One of the lionesses cornered her, but zookeepers quickly pulled the lions inside to prevent more injury to the vulture.
Yatsey, 22, was found with a puncture wound that zookeepers hoped was curable after a checkup upon her rescue.
Sadly, she died from shock while going to the vets after the harrowing ordeal.
Rajang the Orangutan
Rajang, a beloved orangutan, was put to death on December 12, 2018, after suffering from chronic arthritis and other health issues.
Rajang, 50, had been at the Maldon Road attraction for 38 years when zookeepers made the agonizing choice to put an end to his suffering.
Igor the Amur Tiger
The 16-year-old tiger at Colchester Zoo had to be put to sleep after undergoing surgery.
Igor had surgery to remove a tumour on his head, but the doctors realized it was inoperable and had to make the difficult decision to put him down.
Naja the Lioness
Colchester Zoo revealed that week that their lioness had died following a brief illness.
Following a "rapid deterioration" of her health, the zoo's animal care and medical specialists made the tough choice to euthanize Naja at the astonishing age of 18.
After the animal care crew discovered the lioness hadn't been herself for a few days, Naja received a comprehensive veterinarian examination that included blood tests, x-rays, and an ultrasound.
The heartbreaking findings of the diagnostic testing revealed she had significant heart problems and a suspected thrombosis, prompting the decision to put her to sleep.