You know I feel sorry for the folks but its like swimming in the ocean. Go prepared expect the unexpected. In that territory man is not the top of the food chain.
http://www.longislandpress.com/2011/07/07/yellowstone-national-park-grizzly-bear-attacks-and-kills-man/
You hate to hear that. Why would anyone approach cubs... man o man.
The report that I read from the park service stated that the couple unexpectedly came face to face with the mama and cubs. I don't believe they approached them, but more or less rounded a bend and there they were.
Now the authorities will be forced to assemble a team of bear psychologists to assess why on why did the bear do such a thing...We've encroached on their territory enough..this will only get worse as over time bears are pushed out and rendered extinct...all in the name of progress.
It's a shame but nature can be harsh. We enjoy it, but it that pleasure comes with some amount of risk.
Prayers for the family of the fella.