While Bob golfed one day I went and sat by the river at the end of Zion Canyon. After a couple of hours I decided that I wanted some sun, so moved 25 feet down the river.  10 minutes later I heard a roaring sound....I looked up the river to a rock fall from the top of the 2000 foot canyon wall……25 feet away …right where I had been sitting…..It looked like a red 9/11 dust mass coming right at me….Unfortunately my camera was in my backpack so my pics are later in the event.  The sound was so loud and rumbling!!!  I should note that   the rocks only fell on the other side of the river so I wouldn't hve been killled....but I would have died from dust or heart attack....I shook for 20 minutes after it happened....