Yep, I remember when my sister was in high school in the early 80s (decent sized school in texas). Conversation would go like:Threats towards schools have been going on for decades. Weapons of many kinds brought to school and bomb threats phoned in were daily occurrences in the 90's and 2000's.
Parent:- hey, why are you home early?
Sister: Oh, there was a bomb threat before 5th period.
Parent: Oh, OK.
Difference today is there seems like an actual danger of it being real vs someone getting out of a test.