In an earlier thread, it was stated the Israelis once had this problem back in the '80s with Palestinian terrorists attacking their schools and killing schoolchildren. They solved it by arming teachers and having armed volunteer parents and grandparents patrol the school and school grounds of their public schools. Ever since, there have been no attacks on Israeli public schools. The terrorists headed to softer targets.
Note, they didn't put a few more uniformed police in the hallways or beef up their SWAT Teams (who will show up well after the fact).
We won't even consider that in today's political climate. We are going to have to lose thousands of school children in a massive, coordinated attack before our socialist pantywaists educrats would be forced into such measures by parental lynch mobs. So, until then, they will hide their coiffured heads under their pillows and pretend there is "no problem" - just because they wish it that way and have the power to poo-poo it,... just like in this article from San Diego.
Political Correctness reigns in the USA and will until something much more terrible than 9/11 happens. Incredible. Our betters would rather have dead kids in our schools than armed citizens preventing it!
The pantywaist educrats won't have jobs if an incident happens because public education will end as we know it.
Schools are offering on-line courses now, taken in the privacy of your home.