There is a lesson in this report from NBC.

"The campers had been unable to find the vehicle and had become lost in the wilderness after their group leader went over the waterfall."

Sierra Club rules dictate that an assistant leader also know the route, and usually a designated sweep will also know how to get back to the TH.

I have another rule...don't go out unless you have a clue. I have seen the Sierra Club system at work more than a few times. Yes, there was a leader and a sweep but the leader was more than a mile ahead of the sweep and there were trail junction in between, too.

I have run into enough lost and well over their head souls to know the only truly safe way to travel in the wilderness is to be self-reliant.