ADELAIDE, Australia — Sam the koala, who gained worldwide fame and sympathy when she was rescued during Australia's devastating wildfires this year, died Thursday during an operation meant to save her from a life-threatening disease.

The 4-year-old koala had developed cysts associated with urogenital chlamydiosis, which affects up to 50 percent of Australia's koala population.

During surgery, the disease was found to be so advanced that it was inoperable and Sam was put to sleep, said Peita Elkhorne, spokeswoman for the lawyers that represent the shelter where the koala had lived since the February fires.

"It was so severe that there was no possible way to be able to manage her pain," Elkhorne said in a statement. "All of those who have been involved with Sam are devastated with this loss."