CHICAGO — AT 12:24 p.m. today, the Victory Bell at Kent State University will begin tolling in memory of each student killed or wounded when National Guardsmen opened fire on antiwar protesters precisely 25 years ago.
Near the grassy crest of Blanket Hill, where guardsmen abruptly wheeled and fired a deadly 13-second volley, the chimes will echo off an unfinished stone memorial bearing the ambiguous motto ''Inquire, Learn, Reflect.''
As key anniversaries from the Vietnam era rekindle debate over the turbulent period, the Kent State memorial symbolizes a still-unanswered question: Why did militiamen shoot at unarmed students on May 4, 1970?
''Kent State is still haunted by those killings,'' says Alan Canfora, who was among the student protesters that day and was shot in the wrist. ''We can never have true healing at Kent State without the truth,'' says Mr. Canfora, who directs a nonprofit educational organization called the Kent May 4 Center.
Earlier this week, Canfora and other activists sent letters asking President Clinton and Attorney General Janet Reno to make public all official documents on the incident. They also asked that the guardsmen and officials involved be granted amnesty to encourage them to speak freely about the shootings.
The National Guard was dispatched to Kent State amid angry student protests sparked by President Richard Nixon's April 30 announcement of the incursion of American forces into Cambodia. The Guard arrived on campus after arsonists set fire to the Reserve Officer Training Corps building two nights before.
On May 4, a contingent of 28 guardsmen opened fire on students in a parking lot after tear gas failed to disperse a large anti-war rally. Four students -- Allison Krause, Sandra Scheuer, Jeffrey Miller, and William Schroeder -- were killed and nine others wounded. It remains unclear who ordered the shooting and why. An out-of-court settlement in 1979 paid $675,000 to victims and families of victims. Eight guardsmen were earlier acquitted.
This year, the parking lot is the site of a candlelight walk and all-night vigil that ends at midday today. The vigil is part of a week of May 4 commemoration activities that included a symposium entitled ''Legacies of Protest,'' poetry, drama, student rallies, and a concert by the folk trio Peter, Paul, and Mary.
Speakers at the symposium drew various lessons from May 4.
''Kent State is about the use of force,'' says Jerry Lewis, a former student who helped organize the May 4 protest and witnessed the shootings. ''In order for a democracy to survive, we must continue to debate the role and misuse of force in our society,'' says Mr. Lewis, now a sociology professor at the university.
Scott Bills, a Kent State graduate and historian who has written a book about May 4, says the incident should caution us against the myth of boundless tolerance in American society. ''We're not always so free and tolerant. What we're seeing now from the political right is very vitriolic. If this narrows our field of acceptable debate, it will be very damaging.''
Many students at Kent State today, however, fail to learn these lessons because they know little about May 4, a survey shows. Less than a quarter of 200 undergraduates recently surveyed could identify more than one of those killed. Many students hesitated to assign responsibility for the incident. Some said it should be forgotten. A few said those who died ''deserved it.''
Student activists like Lizz Hatton, co-chairwoman of Kent's May 4 Task Force, are working to counter the apathy and ignorance. She says that activists today are better organized than their 1970s counterparts, thanks to the Internet and fax machines, but they face greater disillusionment. ''A couple of decades ago there was a lot more hope,'' she says. ''Now, so many people become overwhelmed and give up, saying, 'I'm not going to make a difference.''' The event should act as a ''wake-up call'' for students everywhere, Ms. Hatton says. ''Of course I don't think it will happen again. But who ever thought the National Guard would open fire on this campus?''