I read somewhere that the best thing you can do is hit the ground. A lot of people start running, and it's a lot easier to hit someone upright than it is to hit them if they are on the ground.

So given that, I would hit the ground and then belly crawl as fast as possible to to cover (behind a car?) and call 911. That said, if the kids were with me in a stroller, I would just break all the rules and push that sucker as fast as I could out of there.

If you heard a gunshot nearby, what is the first thing you would do?