A 2-year-old Amur tiger at the Cheyenne Mountain Zoo in Colorado died in a tragic "freak accident," the zoo announced in a statement Tuesday.

The tiger, Mila, was given a dose of anesthesia on Aug. 25 for an upcoming dental procedure, after which she jumped on a bench to lie down while the anesthetic took effect, the zoo said. But after lying down, she slipped off the waist-tall bench at an angle that caused her to suffer a fatal spinal injury, according to the zoo.

"She could have slid off from that height a hundred times and landed in a variety of other positions and been unaffected," said Dr. Eric Klaphake, the zoo's head veterinarian. "The team quickly entered her den when it was safe and diligently tried for 40 minutes to give her life-saving care."  

Mila, the only cub to survive in her litter, had been sent to the Cheyenne Mountain Zoo from the Toronto Zoo back in March on a future breeding recommendation.

Mila had not yet been seen by guests in Colorado yet, but was close to being introduced to the community when zoo staff discovered she had a serious and potentially fatal dental issue.

Zoo leadership emphasized the amount of thought that went into the decision to administer anesthesia to treat the tiger's dental issue.

"Our team delivered exactly the right amount of drugs to a very calm tiger who had trained for this moment," said Bob Chastain, Cheyenne Mountain Zoo CEO and president. "We have successfully anesthetized countless tigers in this same den, and have never experienced an accident like this. We never take decisions to anesthetize an animal for a procedure lightly, and this is a tragic example of why."

Toronto Zoo staff also mourned the loss of Mila.

"She will be deeply missed by all, and while we feel certain the connections she made with guests will stay with them for a lifetime and were an inspiration to get involved in the fight to save this endangered species in the wild," said Dolf DeJong, the CEO of Toronto Zoo. "We are deeply saddened by her loss."

Mila is the second Amur tiger to die unexpectedly at Cheyenne Mountain Zoo. In 2021, 9-year-old Savelli died as a result of complications during recovery from an artificial insemination procedure. The zoo said it began donating to tiger preservation in the wild after this incident.

Amur tigers, mostly solitary animals native to the Russian Far East, are a critically endangered species in the wild, with just 500 living in natural habitats, according to the zoo. Nearly 100 Amur tigers live in human care in both the U.S. and Canada.

"It is sobering to know that no matter how tragic these events are, that we are losing tigers in the wild every day as these animals, and many like them, struggle to survive in a world where there are so many people and so few wild places," Chastain said.

In:
• Colorado
• Endangered Species
• Tiger
• Toronto
• Canada

Simrin Singh

Simrin Singh is a social media producer and trending content writer for CBS News.