Editor's note: David Rust, a senior cameraman for CNN, has worked with the network since its inception in 1980. He has covered stories in all 50 states and all 7 continents. He is currently on assignment covering the Gulf Coast oil spill.
Atlanta, Georgia (CNN) -- I enrolled at Kent State University in 1967, three years before that fateful day when Kent State became synonymous with tragedy.
Unsure of what I wanted to do with my life, I joined the Reserve Officer Training Corps (ROTC) program, taking classes on military history and planning for a career in the Army.
But everything changed for me that first week of May in 1970.
It was just a few days after President Richard Nixon announced he had authorized the bombing of the Viet Cong's supply lines in Cambodia.
Seeing the action as an expansion of the Vietnam War, some of my fellow students showed their anger by staging a demonstration on Kent State's campus on May 1 that eventually found its way to downtown Kent, Ohio.
Up until then, campus unrest at Kent State had remained relatively minor compared to other schools at the time, which had regular protests stemming from the dissent of the Vietnam War and the turmoil over the civil rights movement.
ROTC students, including myself, were kind of careful around the protests, because we had been warned against the possibility of getting arrested. So we tried to observe from a distance.
As the bars were closing that Friday night, people became unruly and broke several windows. A few students were arrested, but order was eventually restored.
By itself, it wasn't much of a demonstration, but student activists seized the opportunity to make a statement the next night. A handful of protesters set fire to one of the old wooden ROTC buildings in the center of campus.
The Fire Department tried to extinguish the blaze, but after being challenged by rock-throwing protesters, the firefighters felt threatened and left.
The blaze destroyed the ROTC building where I had spent hours in class, as well as working a campus job cleaning rifles.
Video: Kent State then and now
That same night, at the request of Kent's mayor, Ohio Gov. James Rhodes sent National Guard units to the campus. Normally it would have taken a lot longer to deploy the Guard, but the troops had already been activated to deal with an intense truckers strike in Ohio.
Rhodes was also in the middle of an election bid, and clamping down on the destructive protests was seen by many as the politically expedient thing to do.
The troops arrived on campus, many in armored personnel carriers. The images of armed troops on an American college campus immediately caught the interest of the national media.
The National Guard managed to keep the protesters under control the next day, but the stage was set for another protest at noon on Monday, May 4.
I left town that morning, but heard about the events from the national media. According to those reports:
On May 4, as the demonstrators assembled near the burned-out ROTC building, the National Guard troops ordered the protesters to disband.
While many students watched from the sidelines, a much smaller group began to taunt the Guard. Troops chased them up a hillside and down onto a practice football field on the other side of the hill.
When rocks were thrown at the troops, the guardsmen took up firing positions with their weapons pointing directly at the protesters.
After several standoffs, the troops headed back up the hill in the direction of the ROTC building. As they reached the top, they turned toward the demonstrators and opened fire.
Four students were killed and nine others were wounded by the 67 rounds fired in a 13-second volley.
The school was immediately closed and a nationwide strike involving more than 4 million students followed.
Five days after the shootings, 100,000 protesters went to Washington to demonstrate against the incident and the war.
As I watched the four days unfold, I was struck by the images I saw in person and the stories on the national news.
I heard news reports of "thousands" of student protesters, but I had only seen a few hundred in the protests before May 4. Many were like me, just watching what was going on.
It amazed me that the events unfolding at this small university could affect people's opinion of their country and their government.
I was also impressed by the dramatic photos that captured the events, including one shot by John Filo, a Kent photojournalism student.
It showed a 14-year-old girl kneeling beside the body of Jeffrey Miller, one of the dead students. The photo earned a Pulitzer Prize for Filo. It also had a huge impact on the American public.
The power of the media coverage of the Kent State protests opened a whole new world for me.
For the first time I began to think about journalism. Six week later, when school reopened, I began to take my education more seriously. My grades dramatically improved, and I started focusing on a profession. I returned home to California and started taking writing and photography classes at Pasadena City College. The more I learned, the more obsessed I became with the news business.
With the help of friends working for televisions stations in Los Angeles, I learned to operate a television news camera.
Two years later, I heard about Ted Turner's new experiment in 24-hour news, and I started working for CNN's bureau in Los Angeles.
It all started with an unexpected lesson learned from a tragedy 40 years ago.
