The zoo announced staff members had to put down the 31-year-old bear as its "quality of life quickly declined." According to the zoo's director of animal health, the grizzly bear's health had been declining over the past week due to old age and "unknown causes."
Following a necropsy, zoo officials found severe intervertebral disc disease and a tumor in its adrenal gland.
The North Carolina Zoo has been the home of Tommo since 1995 after it was identified as a "nuisance bear" in Yellowstone National Park and was relocated twice by Montana wildlife officials.
"I had the privilege to work with Tommo for over 26 years," said NC Zoo Animal Management Supervisor Chris Lasher, who was there when Tommo arrived in 1995. "He was an amazing, goofy and handsome bear. He never stopped surprising his caretakers with his intelligence and his ability to learn."
The name "Tommo" translates to "winter" in the Native American Paiute language, according to Lasher.
Following Tommo's death, the zoo said the grizzly bear habitat will remain empty until another bear arrives in the future.
"A big bear with an even bigger personality. He was a perfect ambassador to show our guests how truly amazing grizzlies are and what wonderful personalities they can have," said Kelly Nields, Tommo's caretaker of 13 years.