[steve86]

a few years ago, I think on Mt. Ranier there was a rather spectacular helicopter crash trying to "save" some hikers....

You're probably thinking of the Mt. Hood 2002 Blackhawk crash:

In 2002, nine climbers slid into the bergshrund crevasse, which yawns across the base of a steep chute leading to the summit. Three perished, and the military helicopter assigned to extract the remaining injured climbers crashed into the mountain's crater.

[steve86]

That whole episode, BTW, happened along the "easy" south route on Mt. Hood, where people have been known to climb in tennis shoes in good conditions (definitely not recommended; should have ice pick, crampons, etc.).