Phaedrus, the one thing I can think of is if the parents were sick with the toxin and it slowed them down..then the heat took over. Personally, with all of the "signage" about the bad water, I'd be surprised if the parents had any water toxin in their bodies, but we shall see.

I think most of them would be alive if they had gone back down to the water and stayed in it and near it until found or hiked out at night.