One person has died and another has been injured after a rockfall on a popular climbing route in Yosemite National Park, the National Park Service said Wednesday.

The incident was reported on El Capitan, a granite monolith that rises straight up about 3,000 feet in the Sierra Nevada of California. The NPS said a rockfall of “undetermined size” occurred about 1:55 p.m. local time, and park rangers and search and rescue personnel were at the scene.

“The release point appears to be near the ‘Waterfall Route,’ a popular climbing route on the East Buttress of El Capitan,” the park service said. “This is the climbing season in Yosemite National Park and there are many climbers on El Capitan and other climbing routes in the park.”

Park rangers were working to get one injured person to medical care.

The NPS did not identify the victim or injured person and said it expected to release more information Thursday.

Ryan Sheridan, a climber, posted a photo to Facebook with a comment that said the fall “doesn’t look good” and that “one person walked out of the debris.”

Comments on a rock climbing forum said the fall “looked like a sheet of rock about 100 feet square.”

The NPS said Yosemite remains open.