Back when I was a scout leader we decided to take the boys up Angels' Landing. The night before a party of 3 had fallen to their deaths and the whole canyon was a buzz because of it. We emphasized safety to the boys, and I felt that the lesson had sunk in.
As we neared the top on the hike, we saw where the group had fallen, plants ripped out by their roots, scratches on the sand stone, even if we hadn't known those people had died, we would have guessed it from the marks they left.
One of the boys decided it'd be funny to recreate the fall. He jumped over the railing and started acting like he was going over. Only, he lost his footing and started to fall. I was the closest leader to him, and I thought he was a goner. I leapt to where he was and managed to grab his finger tips. I started sliding toward the edge, but luckily I'd had the forethought of clipping my harness to the rail chain. We dangled for about 30 minutes before it took literally all the scouts and leaders to pull us up.
At the top of the hike, I made this scout apologize to everyone, and share his cheetos with me for saving his life. I sure was grateful for my intellect and athletic prowess that day. Any other leader jumps after that kid and they'd both be dead.