The picture in the "Tragic Unicycling Accident" Web page was snapped by a professional photographer, Richard Weeder. The picture is copyrighted; please do not download or duplicate it without permission.
The unicyclist is Kris Holm, probably the best mountain unicyclist in the world. Kris was riding in the Mountain Unicycle Trials in Squamish, B.C. He did not fall off the cliff!
You can find more pictures of Kris doing amazing things in his photo album.