Suddenly a lion in an Australian zoo snaps at a woman.

A woman in Australia lost her left arm in a lion attack at a zoo. The big cat suddenly attacked the 50-year-old woman on Sunday at Darling Downs Zoo in the state of Queensland as she observed several keepers working with the animals in the predator enclosure, the zoo said, calling it an "unexplained" attack.

The victim was reportedly not a regular visitor, but an Australian woman experienced in dealing with lions. She didn't work directly for the zoo, but had known the lions there for 20 years, it was reported. The woman was flown to a hospital in Brisbane, about 140 kilometers away, where she was scheduled to undergo surgery. However, her arm could not be saved, ABC reported.

Authorities launched an investigation. It was not known whether the lion was male or female. It was also initially unclear why the big cat snapped at the woman. However, the zoo posted on social media that the animal would not be killed as a result of the attack. The privately run zoo, which also houses leopards, cheetahs, and a tiger, was scheduled to remain closed on Monday.