Hikers Presumed Dead After Falling Over Yosemite Waterfall

[Updated 9:30 p.m. ET] Three Yosemite National Park tourists are presumed dead after climbing over a guardrail into the Merced River, park officials said Wednesday.

"So far we have seen no clues or no evidence of any of the bodies," said Kari Cobb, a spokeswoman for Yosemite National Park. "We are presuming that all three of them are dead ... we will scale up the search once the water levels have receded and we can insert crews to look for the bodies in the river safely."

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