There was school shooting in my uni last month and I couldn’t breathe for hours.I have experienced a certain situation, trust me guys there would be no saving anyone or any heroics of any kind.
And if you don't believe just observe how people react during shoot outs and when someone brandishes a gun.
There are times when people use others as shields. What about when a gun goes off during an event, it usually leads to a stampede
Yes shop keepers fight back and that's probably because it wasn't their first time in that situation.
If the shooter gave you time to get over the shock for whatever reason, then most people would die trying to save family.