Although the shootings at VTech are horrible. I would not jump to a conclusion that you are not safe in school or anywhwere else in general.
This was a rare incident that when in the news seems to be much more widespread than it really is. In reality the odds of getting hit by lightning are not much different.
Always be aware of what is happening around you and you will be safe 99.99% of the time. You can't really prepare for a 1 in a million event like Monday's horror.
I always say you can't live life worrying about sharks and lightning.