Back to Whirlie’s post.
Look for the available cover in malls. Cement planters, benches, columns and other solid barriers. Use it if you hear shooting. Try to determine if you are in sight of the shooter(s). Fight or flight? Measure your chance of success and the consequences of your decision. Don’t split up your group in the mall to meet later any more.
Every small retail space has an exit in the rear of the store. Don’t use the main mall exits or try to get back to your car through the mall. Just leave the building and look for danger outside before you exit. Go to a safe place with cover away from the shooting. Don’t show the cops you have a gun, they may shoot you and you will be detained until they figure out you didn’t shoot anyone. That could be days.