This sad news article tells about a Marine who was on leave home when he was killed.
He had heeded the advice of commanding officers, "that a Marine on leave might be seen as a prime robbery target with a pocketful of money, so he only carried $8, his military ID card and a bank card." He was waiting at a bus stop with his girlfriend when they were indeed accosted by robbers. "The robbers took his wallet, turned his pockets inside out, took what he had and told him since he was a Marine and didn't have any money he didn't deserve to live. They put the gun to his neck and shot him."
The vast, vast, VAST majority of the time, robbery attempts such as this do not end in murder. This young man was prepared for those vast, vast, VAST majority of times. His plan fell through.
As a self-defense teacher, I'm always asked how best to avoid street crime, or if necessary deal with it. I give options, not answers. Even the best plan has holes, even the best defense has weaknesses. Always think "what next, if . . .?"
Plan, or be planned for.