That is awful! I know what you mean about busy parks...or parks get very busy at times in the summer and I tend to leave when too many people show up. I usually find that before 10am is usually okay. I also have a set of bright orange matching hats for my kids so that they are easy to spot and keep track of. I don't help children who are too small to go on the climbers..they have to play in the sand or smaller play things until they are older as that would require me to focus on that one child and not be watching the others. I also only do swings if the can all swing at once. I am constantly watching, counting, checking and doubel checking. I know how stressful it can be!