Oh wow trying to get me up on my soapbox again, huh? I think you're great Durangobob.
First, just curious, but where did you get your statistics? Site your sources, sweetie, or else we'll think your grandmother made this up.
Second, I agree this is a terrible problem in Texas, not just during the summer months. You asked what is wrong with our society? I say, a whole bunch of things adding up to children dieing. Solutions that may help: an increase in free parenting classes and awareness campaigns about the dangers of leaving your child in a hot car, support and education for parents.
Being a parent is a hard job, being a single parent is just plain tough. Often parents can't afford a babysitter and then sometimes end up leaving children alone at home, where they can face other dangers. Our society is so isolationist and independent that families no longer have the support of extended family members or even neighbors to help with child care.