Koko, the gorilla who knew sign language, dies at 46

WOODSIDE, Calif. (AP) — Koko the gorilla who mastered sign language, raised kittens and once playfully tried on the glasses of the late actor Robin Williams, has died. She was 46.

The Gorilla Foundation says the western lowland gorilla died in her sleep at the foundation's preserve in California's Santa Cruz mountains on Tuesday.

Koko's capacity for language and empathy opened the minds and hearts of millions of people, the foundation said. She appeared in many documentaries and twice in National Geographic. The gorilla's 1978 cover featured a photo the animal had taken of herself in a mirror.

Williams, another San Francisco Bay area legend, met Koko in 2001 and called it a "mind-altering experience." The two hold hands and tickle each other in a widely shared video.

"We shared something extraordinary: Laughter," he says. "Koko understands spoken English and uses over 1,000 signs to share her feelings and thoughts about daily events. Life, love, even death."

"It was awesome and unforgettable," said the actor, who killed himself in August 2014.

Fans mourned Koko's passing, and the foundation's website experienced excessive traffic today.