Why would you suppose that doing that would be of any help to that grieving mother -- even it is in fact true? It doesn't help a parent whose child has died of drowning to tell it that it was an accident and nobody intended it.
We live in a real world, an imperfect world, one in which bad stuff happens. We don't want it to happen, we care when it happens to us, and hopefully we care when it happens to others --- and then we (hopefully) see what we can do to fix it. Will we ever fix everything, forever? I very seriously doubt it. But should we stop trying?