We all like to have (need to have?) the illusion that someone is actually in control of life, maybe even ourselves. The sad reality is that no type of intervention can actually predict what any individual will do.
There have been recriminations about what "someone" "should" have done, after every tragedy. My view is that if "they" could have done it, they would have done it, and tragedy is tragedy.
People, and the suystems in which we work, can LEARN from tragedy, and improve laws and strategies and procedures over time.... but prevention is another matter. Ask any bodyguard-- if someone really wants to kill, they are going to find a way to do it.
Whenever the media is looking for someone to blame-- I always like to try to remember to think of the ones being targeted for that blame. When I look at what happened from the view they had at the time it happened-- most of the time it turns out that they were mere human beans trying to do their jobs the best they could on that particular day, in the face of some other human bean in the grip of an awful drive to do something wrong, who had the edge in creativity.
Looking at other Mudcat threads I often see people wanting to name themselves "God." We ALL want to do that when tragedy strikes-- expect the "responsible" party to have had the prescience of "God"-- and then blame the person we think should have been Godlike that particular day.