A woman in her 50s is believed to have lost an arm when a lion mauled her at an Australian zoo Sunday morning, according to authorities and reports.

At approximately 8:20 a.m., a frightening event took place at the Darling Downs Zoo in Queensland near Towoomba. The victim, a frequent visitor of the zoo, was observing zookeepers attending to the animal when the unexpected incident occurred, stated the zoo.

“This morning, a much-loved member of our family was watching keepers working in the carnivore precinct,” the zoo said in a statement.

The woman had “done this many many times over the past 20 years,” the statement read.

Despite her familiarity with safety measures concerning hazardous animals, the woman was unexpectedly attacked by one of them. The attack resulted in severe damage to one of her arms, as reported by the zoo.

It’s not clear where the woman was standing when she was attacked.

She was airlifted to Princess Alexandra Hospital in Brisbane with a “significant arm injury” and was in stable condition while undergoing surgery.

The animal that mauled the woman was a lion, and the lady is believed to have lost her arm in the attack, the Daily Mail reported.

The lion never left its enclosure during the incident, the zoo stressed.

The animal will not be euthanized, the Daily Mail reported.