In answer to the question about the morality of harming one to save many:
Let me rephrase the question to answer it and many others by making it broader:
Is it moral to hurt some (possibly killing them) in order to save others?
Yes. If the action is intended to save the others and not intended to hurt the some and if the hurt is not certain, possibly predictable, but not certain. (If the hurt is certain, then the others are being deliberately valued more than the some, and that is immoral, regardless of the numbers involved.)
In other words, if the ultimate goal was that all may be saved, but the actual result is that some are hurt or killed, even if there was some predictability of such collateral damage, then, as long as reasonably sound judgment was used, the injuries or deaths were not the result of immoral action.
Note that, if professionals are making the judgment, then the bar of "reasonably sound judgment" is higher--but then so is their latitude in using that judgment. That is why we have professionals.
JMO on morality.