A female polar bear living in Assiniboine Park Zoo in Winnipeg died during dental surgery under anesthesia.

The zoo confirmed that the nine-year-old polar bear Aurora died on Tuesday.

Grant Fornes, Senior Director of Zoological Operations at the zoo, said, "It is always sad when we lose animals in the park, and in this particular case, it was more difficult given the circumstances in which she died."

Aurora had suffered from recurring dental problems since she was rescued and brought to the zoo as a cub in 2013.

The zoo said it believes her teeth were damaged from eating rocks and sticks in an attempt to survive without her mother.

According to Fornes, Aurora had many previous dental procedures to relieve her pain, treat infection, and prevent her dental problems from developing into life-threatening issues.

The zoo said Tuesday's procedure was done under anesthesia and with the assistance of a specialized veterinarian.

According to the zoo, the procedure went well but as the team was preparing to reverse the anesthesia, Aurora suffered a cardiac arrest.

Fornes said, "The veterinary team did everything they could to save her, but unfortunately, she passed away."

Fornes added: "We will investigate the causes of Aurora's death."