But after a gunman sprayed bullets at thousands of people attending a country music festival in Las Vegas last night, the question is whether you would know what to do if you caught yourself in a similar situation.
"It's virtually mission impossible," security expert and former FBI agent Jim Conway says.
Run, hide, fight: Protect yourself in an active shooter situation
Unless you can safely and successfully take down the shooter, Conway says there is only one real form of defense: have a plan and act fast.
"Think ahead of time. Create some situational awareness," Conway said. "What am I going to do if something bad happens in here? Whether it's a shooting or a fire or an alarm. When we analyze these things and we look, it's always the people that were able to react first, we look back at the Aurora theater shootings, those are the people that survive."
The key, Conway says, is to know where you will exit and spring to action.
If you remain frozen without a plan, your chances of survival are greatly reduced.
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