So this is the excuse that pardons the guardian's lapse of attention? So how many minutes are they allowed to misplace their child before it becomes negligence and they begin to assume the blame? What about the gate being removed for construction? THIS COULD HAPPEN TO ANY POND OWNER. Apparently you don't get it... this idea of responsibility I mean. One minute or one hour, its still the parent/guardian's responsibility. You want to help direct traffic in front of your house, fine... you put the toddler into the house FIRST! or you find some other responsible person to monitor the child's activities or you pick-up the child and take him with you. If you choose to blow off that responsibility YOU should be held negligent regardless of whether you go off for 4 minutes or 40 minutes.... it has nothing to do with how long you ignored your responsibilies.
You (and others) keep going back to the law as your defense for your moral conclusions... as if the law is always the correct moral judge. In Kohlberg's stages of moral reasoning, reasoning based on authority was considered only at second level reasoning, stage 4... its the same level used by people who helped carry out the holocaust in WWII... their excuse was that the law/authorities directed them to put others to death therefore they felt they were not to be blamed for the genocide they had participated in. The highest form of moral reasoning (meaning the end of the series) is based upon universal ethical principles at a level 3, stage 6. According to Kohlberg's theory one cannot comprehend any stage of moral reasoning further than one stage just above their own stage of reasoning abilities... if Kohlberg is correct in this then I'm wasting my time here.
What really saves human lives is responsible parenting and owning up to one's mistakes and vowing to do better instead of just blaming others and enacting laws that penialize others for one's own failures. So perhaps one could say irresponsible parenting is really the number one cause of death amoung children under the age of 5 and thus why so many small children die by drowning. I mean, how can a child die by drowning if a parent/guardian is watching?