If you do find yourself in a critical event in an open setting, here are some things to do that will increase your chances of survival.
Overcome your normalcy bias- normalcy bias, in a nutshell, is your inbred resistance to recognizing a threat immediately. Las Vegas is a perfect example. The shooter was well into his second and third full-auto course of fire before most folks at the concert realized what was happening. You could hear people discussing whether it was firecrackers or stage props. A full explanation of normalcy bias is beyond the scope of this post… suffice to say, that the longer it takes you to recognize a threat, the lower your chances of survival. Seconds count.
Stop, drop, find cover- Panic-stricken flight is not the answer. Once you realize there is a threat, stop what you are doing, get low, assess the situation. Where is the threat coming from? Where are your nearest points of cover or concealment? Once you have made a rapid assessment, get to the nearest cover or concealment. There you can re-assess, and decide your next move. Remember, cover is something hard, that can protect you from gunfire. Concealment is something that will not necessarily protect you but hides you from active sight of the threat.
If you have ignored the best advice and wore those high-heels, flip-flops, or cowboy boots, now is the time to remove them. Give yourself the best chance to run effectively. Loose clothing can snag on obstructions. If you can, take it off.
Once it is time to escape, run away from the crowd. Don’t follow the pack. If there is a stampede toward your first exit option, go opposite, or perpendicular, and use your second, or third options.
Sometimes the best way out is through. A ground floor window, a weak point in perimeter fencing, through vendor areas, or the backstage and out the artist exit. Concert security will most likely want to help at this point. Avoid long hallways, and “funnels”. Avoid running with the crowd, or parallel to it.