What was the worst "threat" you can recall circa 1967, be it MHHS, the college you attended, etc?

In the fall of 1971, when I was in a hospital rehabbing, there was a tragic shooting in St. Aloysius Church on the Gonzaga University campus. The caretaker was shot and killed in the church, then the shooter climbed to the top of one of the spires and began shooting at students below. No students were killed but Spokane police ended up killing the man.

Seven years later I would be a student there.

UT Tower in Austin!

The scariest thing that happened while I was in HS was Kennedy's assasination.
In college, although I wasn't there, was the Kent State killings.