Sadly you're mistaken. Not many current American adults experienced them growing up even though school shootings have been happening for decades, but in recent

Sadly you're mistaken. Not many current American adults experienced them growing up even though school shootings have been happening for decades, but in recent years they've started to become as commonplace as fire drills in American primary schools. "Nine out of ten public schools now drill students and teachers to respond to mass shootings, according to the National Center for Education Statistics." [regrettably via Vox: https://www.vox.com/policy-and-politics/2018/2/16/17016382/school-shooting-drills-training https://www.vox.com/policy-and-politics/2018/2/16/17016382/s... but still, seems legit]