In the uk, where there are stricter laws, this kind of thing doesn't happen. Yes there are people/gangs carrying guns illegally but there are very few cases of people being shot (that aren't involved in gang culture themselves).
It says something that even the majority of our police force do not want to be armed with the main reason being that they believe arming themselves will encourage more criminals to starting carrying weapons.
I feel for these children and their parents, and the people that had to deal with the aftermath and seeing that sight. It must be devastating.
Life is not measured by the number of breaths we take, but by the moments that take our breath away.