Discussions

I was recently fishing at the Hydro park. A family consisting of the parents, a young girl about 13 and a boy about 3 arrived at the Hydro damn with butterfly nets, obviously out for some fresh air with the family. Not long after arriving, the parents went for a stroll down the lane, while the daughter went around the corner to collect bugs. This left a 3 year old boy with no life jacket standing on the bank of the flowing river by himself. Neither his parents or his sister could see him from where they were. His parents were gone for about 10 minutes, and not once during that time did his sister check on him. My boyfriend and I watched with worry as the boy stood on the bank of the river throwing rocks into the rushing water. He was right on the edge, and lost his balance a couple of times, but thankfully fell back onto the bank rather than into the water.  
I just couldn't believe the parents of this boy were so careless! If the child had fallen into the water the parents wouldn't even have heard him they were so far away! I was very tempted to give these parents a lecture when they returned, but didn't want to cause a scene in front of their children. Should I have said something?