When this was on the news the other night, I called my daughter into the room. I wanted to reiterate our rules (I didn't need to, but she's only 7 and a reminder never hurts) and why we made them regarding the pool. I also wanted her to see and hear it for herself, that kids (and adults) do drown, and it can happen in the blink of an eye.
Our rules for her are simple - if she is in the pool either myself or my wife has to be watching her, and if we have to do something else or go inside even for a minute, she has to get out and wait for us to come back, and absolutely no going in if for some reason we can't see the bottom.
She's been told several times, but it was another chance to drive that point home. This is why we have those rules. If we aren't watching, then if something happens we probably can't get to her in time. And if we can't see the bottom, we may not know anything is wrong until it's too late. Especially as much time as she spends underwater! She's a very good swimmer, especially for her age. But you just never know...
Btw, these rules also apply anywhere else she swims. An adult we trust has to be watching her, and if their pool isn't up to our standards, no swimming. If they get their feelings hurt over why we won't let her in...too bad.