On May 22, 1983 a group of people rented rafts to run Slippery Rock Creek, a Class III-IV run in Western Pennsylvania. The river , initially running at moderate levels, rose to was 5.0 feet following heavy spring rains. the high water caught the group just below McConnell's Mill in a very fast section known as "the Mile". One of the rafts flipped against a midstream boulder and pinned hard. William Presto, 20, fell out of the raft. But the perimeter line had unraveled, and it became tangled around his ankle. There he dangled in the fast current until he drowned. The other rafters floated free, but because of the speed of the water were washed some distance downstream. It tpook a long time for them to work their way back upstream and by then it was too late.
Loose lines are extremely dangerous in whitewater. Everyone, especially rafters, should see that ALL rope is secured. Paddlers should carry a knife to deal with this sort of emergency. Despite the unexpected rise in water the victim would have survived if the line had been secured, or if a persin carryiong a knife had been available.