A lioness at a farm owned by the Johannesburg Zoo killed a 65-year-old zookeeper, a zoo spokeswoman said Tuesday. Joe Ramanata had worked at the South African zoo for more than 40 years. He was declared dead when he arrived at the hospital shortly after the attack on Monday. The zoo spokesman said Ramanata was either feeding or cleaning an enclosure. Another spokesperson suggested it could have been human error that contributed to the attack, since the enclosure did not appear to be locked properly. The lioness, 11, was tranquilized after the incident, and the zoo managers will meet to discuss the lioness’s fate.