From Kent State University's 50th Commemoration Exhibit.

Sunrise brought a fragile calm to the Kent State University campus, and the warm, breezy spring day lured students out of their dorms.

Laurel Krause, whose sister, Allison, was killed during an anti-war protest, seeks answers to why the National Guard gunned downed students.

From Kent State University's 50th Commemoration Exhibit.

Sandy was walking near the demonstration when the shooting began and she was tragically caught in the gunfire. When the family heard of the shooting, they thought of nothing their daughter.

andra Scheuer. When most people hear her name, they think of May 4, 1970. They think of how she and three others were killed by the Ohio National Guardsmen after they opened fire on unarmed Kent State University students. But, to my grandma, who was a senior speech therapy student in 1970, Sandra was just her young, bright and bubbly 20-year-old classmate at Kent State.

From Kent State University's 50th Commemoration Exhibit.

One of the most iconic photos in American history was taken 51 years ago on May 4, 1970.

Jeff Miller woke Monday morning, slipped on a red cowboy shirt, denim bell bottoms, boots and a brown headband to hold his long hair in place. A rally was scheduled for noon at the Kent State University Commons. He intended to be there.

From Kent State University's 50th Commemoration Exhibit.

Now this was how college life was supposed to be, Bill Schroeder told his sister, Nancy. In a letter that traveled a week earlier from his room at Kent State University to hers at the University of Kansas, he wrote of how he’d been spending the spring quarter learning photography with a borrowed camera, attending evening lectures, going to concerts and joining general “bull sessions” around campus.