While some would say that the extreme behavior of the students on that Day in 1970 caused the deaths, I can only think that these were students. They carried books, not guns. They were idealists. They were at risk by being eligible to be drafted and sent to a war that they didn't understand and they knew would be a tragic failure.
Some students committed violence that weekend. The ROTC building was burned, students shouted, sang with the passion of enraged youth. They were shot on the school commons, not on a battle ground, not behind a bunker, not holed up in a hideout in the hills. They were unarmed.
This diary is a good summary and worthy of passing along.