Officials at Chicago's Lincoln Park Zoo say they were forced to euthanize one of their gorillas this week. Zookeepers say the 7-year-old gorilla, named Mumbali, and her 9-year-old sister, Rollie, became ill about three weeks ago.
Zoo officials said Rollie appears to be recovering, but Mumbali kept getting worse, despite intravenous medications, blood transfusions and even dialysis. Curators said Mumbali was euthanized on Thursday. None of the zoo's other gorillas show any signs of illness.