I was at the Navajo Reserve about 5 years ago. No fence! I stayed on the trail and took pictures where it was clear.
I saw one very overweight kid (400lbs) trip and he was rolling towards the edge, but he did manage to stop in time. Another guy I saw, was leaning over the edge, as if he was an eagle. My thought when seeing him was, “What if a sudden wind passed by as he was leaning forward?”
I saw something similar at Grand Canyon years ago. A little kid, maybe 4 or 5 years old with his feet on the guard rail looking into the canyon. If he had slipped he would have been gone immediately.
I mentioned “Oh please little one, don’t put your feet there as you might slip through!”
The father heard me and chewed his kid good. Pop had been too busy looking at the canyon.
Then my wife proceeds to slip and slide toward the edge in an unguarded spot. Luckily she stopped before she hit the edge.