If you were at a playground and saw teenagers playing around and doing things that could potentially harm the equipment or other children, what would you do, if anything?

I was at a playground yesterday (late on a Sunday afternoon) with my 7 year old and two adult friends. There were a bunch of children and their parents and there were also two groups of teens hanging around. One bunch of teens were climbing on the outside of this wooden structure, probably 20 feet above ground level. It is a structure where kids can climb up inside it and around on a balcony type thing. It’s definitely not intended for people to climb on the outside of it. If one of the teens fell off, they could land on a kid or of course, injure themselves.

There’s also a zip line contraption where kids can pull themselves up onto a hanging thing that slides along a zip line. The thing has a sign that specifies that it’s for 3 to 12 year olds. There were 3 guys, probably 15 years old each, so probably about 150 lbs if I were to guess. 3 of them were hanging on the thing at once. If it’s made for 12 years old, maximum, then I would guess it’s made for maybe 120 lbs, maybe, since it’s probably made well, it can carry 200 lbs, tops. 3×150 = 450 lbs. Too much.

If you saw stuff like that happening, what would you do, if anything?

I will post later what I did and what my opinions are. I don’t want to taint the thread before hearing what other people have to say.