Everybody could come into mall. I wouldn't let my child study there since I wouldn't know what kind person she/he will meet. That's why nobody here do such things. Every town has their specialty area for the locals. That's why we buy house in a good town for most Asian people or higher income people.
In US, everybody is recognized and socialized within their comfortable zone. That's the fundamental cuture difference between US and China.
As to the tragety in Sandy brook elementary school, that could happen in anywhere even in China.
