Yosemite Campers Killed by Falling Tree Limb

The campers were hit by a branch in Upper Pines campground.

— -- Two young campers were killed in Yosemite Park when a tree limb fell on them early Friday morning, officials said.

Around 5 a.m., a limb from an oak tree fell in Upper Pines campground in Yosemite Valley the park said in a statement. The branch hit a tent where two minors were sleeping, killing them.

Nearby campers called 911. When park rangers arrived, both campers were already dead.

No further information about the campers, including their ages, was immediately released.

"Our thoughts are with the families as they grieve this tragedy," stated park Superintendent Don Neubacher.

Officials believe California's extra dry conditions may be the cause for Friday's fatal accident.

ABC News' Tom Liddy contributed to this story.