Today is the 39th anniversary of the infamous killings of four student antiwar protesters at Kent State University by members of the Ohio National Guard. Nine other students were wounded, one of whom suffered permanent paralysis.

Some of the students had been protesting on campus against the American invasion of Cambodia, which then-President Richard Nixon had recently announced in a television address on April 30. Other students who were shot had merely been walking nearby or observing the protest from a distance.

The killings helped galvanize antiwar sentiment even further especially among young people, as hundreds of universities, colleges, and high schools closed throughout the United States due to a student strike of eight million students in protest of the shootings.

At the time, The Nation called for indictments and a re-evaluation and re-regulation of each state’s National Guard so as to avert future tragedies. And in his Archivist blog, Jeff Kisseloff illuminates the human dimension of the murders through a conversation with the mother and boyfriend-at-the-time of Alison Krause, one of the four students killed.

This video captures the intensity, tragedy and chaos of the day.