Recently in BC, we have a had a child die in the care of the state. This does happen from time to time, and when it does a process is triggered whereby the Representative for Children and Youth lanuches an investigation and makes recommendations which usually result in more rules and procedures to govern the child welfare system with the express purpose of never having it happen again.
I work closely with child protection social workers in BC and there is not a single one I know of whose heart does not break when something like this happens. Everyone wears the failure. Social work is difficult not because of the kinds of predictable situations that can be mitigated but because of the ones no one saw coming. The Ministry of Children and Family Development operates under a massive set of procedures and standards about social work practice. But no amount of rules will prevent every case of child death. Just like no amount of rules will eliminate every case of discrimination, every war, every instance of every bad thing that happens to humans.