Often we see, especially after the talking points become stale, the real heros come out of the woodwork, humbly.
Sgt. Heinrich was on the campus, off duty, unarmed (failure to be prepared on his part) working on the baseball field when he heard gunshots. He helped a shot student and then met up with a swat officer who gave him kit and a firearm, then they went in to find the killer.
That is what you are supposed to do. You are supposed to do everything in your power to help, to stop the threat and your training should support all of it.
This is why you carry, this is why you stay prepared.