I caught up with an old friend recently, Michael Lemieux, who attended Kent State about 10yrs after 4 students were shot.
The news that Richard Nixon was sending troops to Cambodia caused a chain of protests in the U.S. colleges.
At Kent State the protest seemed more violent, some students even throwing rocks. In consequence, The Ohio National Guard was called to calm things down, but the events got out of hand and they started shooting. Some of the victims were simply walking to school. The photo shows 14-year-old Mary Ann Vecchio kneeling over the body of Jeffrey Miller who had been shot by the Ohio National Guard moments earlier.

By John Paul Filo
Check them all: Images That Changed The World
Kent State [1970]