A lioness attacked and mauled a 63-year-old zoo keeper to death at a farm owned by Johannesburg Zoo in South Africa.
Joe Ramonetha, who had worked at the zoo for more than 40 years, died from a bite to the neck, zoo officials have said.
He was taken to hospital but was declared dead on arrival.
A zoo spokesperson said Ramonetha was either feeding or cleaning an enclosure when he was attacked by a lioness.
Louise Gordon for the zoo said the tragedy may have been caused by human error as it appeared that one of the enclosures was not locked at the time of the attack.
Gordon told Volksblad newspaper that Ramonetha was a much-loved member of staff, and zoo employees were in mourning.
"We're very shocked, because he had decades of experience and training in various safety procedures. We don't know what could have happened," she told the newspaper.
The 11-year-old lioness was tranquilised after the incident and moved to a separate cage. Zoo managers are planning to meet and decide its fate.
The incident happened on Parys Zoo Farm, a breeding farm in the Free State Province, about 120km (75 miles) southwest of Johannesburg.
Police have opened an investigation into the death.