It's not so much about how good or how bad you secure your weapons. It's about how likely are you to become insane when you have access to weapons. It seems to me that adults have been active shooters as often as children.

Note that in most of the geographic US, concealed carry is the norm, not the exception:

https://upload.wikimedia.org/wikipedia/commons/8/8c/Conceale... (blue and green are either constitutionally protected rights, or the state is legally required to give a permit)