That's a pretty interesting story. The kids who were shot and killed were over 80 meters away from the National Guard soldiers. Same with a lot of the kids who were injured. They were quite a ways away. I'm thinking the National soldiers shot over the crowd that had gathered.
Interesting story, when I taught at Kent State there were bulletin boards listing events and notices. One of the notices was asking for students to join the National Guard. This was a few decades after this event though.