I agree you have to play the odds. When I play the lottery, it is when the cash prize is so high that tossing a few dollars (cost) seems trivial relative to the benefit of winning, even if the odds of winning haven't changed. I think this is the reverse of that scenario.
I'm in Argentina and am completely out of the loop with respect to the bliztkreig of news reports and face to face accusations and calls for heads. I'm not at all concerned with whether mistakes were made. My only concern is whether it is possible to come up with contingency plans that will circumvent worst case, less than worst case scenarios.
There is nothing like having a woman who is observant and has her mind clear to prevent a disaster in her realm (the woman who saw the gunman and instead of turning into a Hollywood actress, turned the table against the door). Most problems can be prevented with on-site vigilance, and proaction. The President of the University of Texas just sent out a letter describing everything they have in place to counter problems like this shooting. Then he points out that the solution is everyone's:
"The greater challenge in emergencies is with individuals not knowing personally what to do if they find themselves in a threatening situation or if they have noticed a significant, strange change in someone's behavior."
He then gives a webpage that offers protocols for action.
I believe this type of education is the first step. Having everyone aware of the fact that each of us is our best friend and each of us may be the last defense against horrors like this is a necessary assumption. There is plenty of blame to go around but personally, I like to look at myself first and ask, whether I could reasonably have anticipated the problem, reasonably done something, or even reasonably not put myself and others in further danger.
Some problems come without warning. These are best dealt with by those directly facing them. Problems that can be anticipated or predicted, especially with fairly good timing, are first dealt with by the group. In Central Texas, we have lots of tornado warning systems. We don't expect tornadoes during clear sky but we increase our vigilance during storms. When there are weak points in communication, it is up to the group, that is all of us, to determine whether that weakness can be reasonably addressed. If it can't, we might as well attribute those deaths to fate. If the weakness can be addressed, we have to assume that if we let that weakness stand in the future, we have failed and the deaths are on us.