Ex left our 7 year old unattended at a water park

I’m not sure for how long our seven-year-old said it was for kind of a long time. Apparently the nine-year-old wanted to go on a ride that the seven-year-old was not big enough to go on so my ex-husband told her to stand there and watch the tubes, while he and our son went on the ride. This is not the first time he’s made questionable safety decisions when it comes to the kids. I’m going to email my lawyer and let her know but I’m not really sure what I should do next. I’m not sure if this is even something that the court would be concerned about. I am worried that something bad has to actually happen before I can do anything to protect my kids. Our seven-year-old is not a very strong swimmer. Not to mention the whole kidnapping risk. I don’t think I’m overreacting to this, am I? When it comes to my ex, I am extra critical about his parenting style and choices.