KENT, Ohio (AP) – The campus bell tolled Friday for two tragedies separated by a generation as Kent State memorialized its four dead at the hands of Ohio National Guardsmen and the 32 killed at Virginia Tech by a gunman.

The Kent State Victory Bell rang 32 times at midmorning for last month’s victims of the Virginia Tech shooter, who took his own life, then rang again at midday for the annual commemoration of the May 4, 1970, shootings at the Ohio college.

The afternoon ceremony on the 37th anniversary of the Kent State shootings, which happened during a Vietnam-era war protest, had the feel of an anti-war rally as speakers denounced the U.S. war in Iraq and called for student activism to halt it.

“This has got to be a peace movement,” said anti-war activist Cindy Sheehan, who choked up as she recounted the death of her son in Iraq. “What an honor it is to be welcomed into the Kent State family.”

Fellow anti-war activist Tom Hayden urged students to lobby against the war.

The Virginia Tech commemoration was scheduled to coincide with the time of the second of two fatal attacks there April 16.

“I choked up. It’s an emotional thing,” said Sarah Lund-Goldstein, a Kent State senior and part of the campus group that organized the commemoration. “We feel it’s very important to understand that a grieving campus is not just one from 37 years ago.”

A crowd estimated by police at 200 to 300 sat on a sun-drenched, grassy hillside and heard speakers memorialize the Kent State students.

Mary Ann Vecchio, 51, of Miami, the subject of a Pulitzer Prize-winning photo showing her with arms outstretched over the body of shooting victim Jeffrey Miller, told the gathering her experience on the campus that the day in 1970 will always be with her.

“Time has passed. Time goes on. We miss you here today,” she said, invoking Miller’s memory. “I’ll always be here at Kent for you.”

A survivor, Alan Canfora, said this week that an analysis of static-filled audio from the 1970 campus shootings revealed a military order to open fire. It has long been a mystery what prompted the 13 seconds of gunfire.

After the shootings, the FBI concluded it could only speculate on whether an order was given to fire. One theory was that a Guardsman panicked or fired intentionally at a student and that others fired when they heard the shot. Eight Guardsmen were acquitted of federal civil rights charges.

Canfora, 58, one of nine students wounded in the shooting, located the tape in Yale University’s archives about the event. He has called for new federal and state investigations.