Thought that this story was a tragic situation and proof of what dangers arise when ropes are added into a dynamic environment. A simple throw rope thrown to someone inexperienced in handling one and not having a knife. A main reason why I don't prefer to throw a rope to someone without a knife.
My point is, "ropes can become a danger on the water very quickly."
They were also on the Clackamas going down a normally simple class I+ section but at 10k. High Rocks becomes very dangerous. My first experience into whitewater kayaking was in grade school when a friends dad who kayaked the Grand Canyon and others runs as I was told then class IV boater. Drowned at High Rocks while kayaking. He was pulled under by the boils that form at higher flows and will take you under the shelves and pin you there. A good friends mom use to be a rescue diver that has recovered bodies from High Rocks years back and she said it's pretty creepy down there.
http://www.kgw.com/news-local/stories/kgw_061108_news_boy_scout_drowning.205543d6.html
