Tragedy, no doubt. But launching at 4:30- PM???? We call these tragedies "accidents" but you just know there was some serious operator error going on, also known as bad judgement.
The time of the day was one thing. But that launch is bad-butt under even the best of conditions---it's basically in the middle of a Class III rapid: before you even think of getting in your boat, you better make sure your oars are properly seated in the locks and that absolutely NOTHING is sticking out past the gunnels of the boat because the current is "swollen" even in medium to low water conditions
Short answer---you do not even think of putting together your rods until you're safely anchored downstream. The rapids push you immediately into the bushes below the launch ramp ---as soon as you take your first stroke on the oar you have bushes in your face---
You can picture what happened--- the rods hung in the bushes, guy in the bow lunged for them, the guy on the oars might have lost his concentration--- that and the passenger's lunge probably capsized the boat.
I do a launch like that up in Alaska when I do my 6 day raft trips--- everything looks so peaceful---glassy smooth pool etc, but as soon as the raft is in the current you get immediately pushed into the bushes (trees) below the ramp. All systems have to be "go" when you push free of the ramp---oars in a tight fist, bow properly oriented, blades in the water with firm purchase.
Every year I try and remember that dynamic---- I leave all my rods in their tubes until I'm well below the launch.
Yes, prayers for the guy's relatives but try and imprint the mistakes they made that day between two banks of a river between your own two ears---it might save your life some day