For over two decades, WCS conservation scientist Andrea Turkalo has dedicated herself to studying and protecting the forest elephants of Dzanga Bai, in the Central African Republic. This spring, for the first time in her history there, Turkalo got word that armed rebels were heading her way. She grabbed six hard drives, packed with more than 20 years of data, and fled.

On May 8, a gang of poachers killed 26 of the forest clearing’s elephants. “I’m sure some of them were individuals I knew,” says Turkalo, who learned of the killing in e-mails from local contacts. Guards at the site had previously been disarmed by the rebels, and were unable to stop the slaughter.

Discover Magazine reports on this harrowing story.