Maybe we should start teaching our children to play dead,

[Eleanors38]

8. Frankly, we should take a more serious look at what our actions will be...

No one solution or strategy will always work, but perhaps -- given a crowded room of adults -- if 10% of the people rushed or threw stuff at an attacker, it might be enough to lessen the damage. Rushing an attacker or the source of danger is, I believe, what is taught in the military and by LEOs. Of course, a hostage situation complicates matters, but at the onset of an attack, the would-be killer might be surprised as much as the victims. Mass murderers look for easy targets, and expect behavior repeated in prior attacks. The VT killer was reported to have chuckled softly as he wandered to from one prone, piled up victim to another, casually shooting them.

Future defensive actions are worth considering.

ON EDIT: No mention of defensive gun use was made in this post.