Here's a video taken by a British mountain climber. He was hit by a chunk of ice dislodged by a climber above, and slid/fell some distance. It was all caught on his helmet camera.

Two links: Yahoo News: The Sideshow, Mountain climber's scary fall caught on video

British Mountaineering Council: Winter safety: a scary point of view

Parsley Fern slide on Vimeo on Vimeo

Parsley Fern slide on Youtube: