My feeling is that even if they were misguided or careless in some way, I can't see any purpose in focusing on the the parents' actions. As others have suggested, who amongst us can, hand on heart, say they have never lost concentration or made a mistake and potentially put their children's safety at risk? And, even if there was no carelessness involved, the "if only I had/hadn'ts ....." will go over and over in these poor peoples' minds, probably for the rest of their lives.
If we are upset about the tragic death of this little boy, who we didn't even know, imagine how devastated his family must feel.
What is a reasonable minimum spend for an online grocery delivery??
Lack of public toilets in towns.