What is this world coming to??

Today, Joshua brought home a letter from school. It basically explained that a 4th grade student had been approached by two men in a car while he was waiting for his bus. The men asked him to get into the car and he refused. Just about that time, the bus arrived and the police were called. How scary to know that anything can happen to your child while waiting for the bus. When Joshua got home from school we had a reminder conversation regarding never getting in someone's car, only leaving school with mom or dad (unless he's been told otherwise), etc. He says he understands, but he's such a soft hearted kiddo that I fear for what could happen.