The Department of Homeland Security has sponsored the linked video which describes what to do in the event of a shooter entering an office building. The suggestion of run, hide and as a last resort to improvise weapons and fight. The scenario presented shows how this should work in a perfectly handled situation.
I call BS on this entire thing. Run, hide and fight is the strategy that has been employed by every dead person in a mass shooting in history. It is nothing more than a strategy that is tantamount to suicide.
A better plan infinitely more likely to prevent your murder is what I like to call Arm, Intercept, Destroy. Private citizen packing whatever caliber of firearm with as many rounds as they deem the need to carry will be much better able to engage a would be killer and put that jerk down before they empty rounds into targets at random.
Remember that..Arm, Intercept, Destroy. It kills the bad guys every single time. Brought to you by the 2nd Amendment..guarding Americans against Tyranny and Murder for 200 years!