I hadn't heard of this until seeing it in an newsfeed(?) article called "10 Good Things that Happened This Week".
It seems like there's been several examples of someone drowning around the various falls or in the Merced river in recent years; here's a boy who didn't drown:
http://www.mercurynews.com/breaking-news/ci_23016213/san-jose-teen-recounts-saving-boy-from-certain

