They are actually more common than you think but they typically happen in urban minority areas.
Shooting in the vicinity of a “white” school = LOCK DOWN!!
Shooting in the vicinity of a “minority” school = Nobody heard or saw nothing
I lived near a minority middle school and it was locked down quite often. I’d hear a bunch of sirens and a sherriff’s deputy car would come screaming up, block the road going to the school and the deputy would jump out with his shotgun and stand guard. Every few weeks or so. Normal occurrence and usually a one on one thing or black on black. Punks with handguns going for a specific target. Not some mentally unstable kid planning on shooting as many as possible.