Public ranges scare me. You just never know about the other shooters on the firing line. The fundamentals of safety as I learned them are:
1. Treat all guns as always loaded.
2. Don't cover anything with your muzzle that you are not willing to destroy.
3. Keep your finger off the trigger until your front site is on an identified threat.
4. Be sure of your target. Know what is behind it. Know what is around it.
Just about anytime something goes wrong on the range it is a violation of one or more of these safety rules. Hot brass is something we have (or will) encounter for certain at some point in our shooting lives. Decide now how you will react. Adhere to rules, and while you might suffer a minor burn, you won't shoot the poor bastard sweeping up the range... Yet another good reason to carry an Individual First Aid Kit (IFAK) at the range!