Is all change good?

This year has many situations of change, hell we have a black president name Barak Hussein Obama, that can actually speak properly. As of late there has been a movement within south Florida, a movement of violence. Starting with the shooting at my high school, Dillard, there have been many acts of safety issues. The day after the Dillard shooting, another student at Miramar High brought a gun into school, then the day after that a third grader at Walker Elementary School also brought a gun into school. The following week, on Monday at a Miami school, a student was found unconscious in the bathroom, and he was rushed to the hospital. Now the news stations are talking to students about safety and how the students feel, the talk of the land is about school safety.
My question is : why do students feel the need for protection to the point of requiring a weapon? Do we as a culture have the to have hold of a deadly utensil in order to feel safe? It doesn't make sense to me, can times really that bad within school systems that children feel unsafe within its borders?
Are there reasons for these situations?