More than 400 mourners, most of them students from W.T. Woodson High School, stood silent in the numbing consolation of the rain yesterday afternoon as 16-year-old John Svec was buried in Fairfax Memorial Gardens.

Huddled around the canopy that shielded Svec's grave, so tightly that they crushed banks of flowers underfoot, Svec's friends and schoolmates pressed together for strength. It was the sudden and meaningless way John Svec died that stunned his friends. He was struck by a car as he walked along Little River Turnpike Friday night. The driver, who was first charged by county police with driving while intoxicated, was charged yesterday with involuntary manslaughter.

As the steady drone of the rain on umbrellas drowned out the ceremony, John Svec's friends, too young to be stoic but too old to shrug off death, turned to each other for support. Unused to their suits and ties, the girls' high heels tugged by the mud, the teen-agers at Svec's funeral seemed always to be puzzled, uncertain, reaching for something--facial tissues, words, hands, Svec himself.

"He was one of the nicest guys I know," said fellow Woodson sophomore Joyce Ferguson. "He wasn't 'popular,' he was just a very well-liked, loved, person. Everybody had an association with him."

John Svec's friends are also reaching for ways to make him a rallying point in the growing controversy over drunk driving.

In the past few days, the students at Woodson have launched a series of protests, demonstrations and antidrinking campaigns that they hope will prevent any further accidents.

Using acronyms such as SADD (Students Against Drunk Driving) and FADD (Football Players Against Drunk Driving), they hope to shatter the old high school traditions of beer parties and illicit alcohol. SADD was formed after the death of another Fairfax County teen-ager last year.

"It makes me mad at myself to think that it took the death of a friend to make me realize what a deadly weapon alcohol is," said sophomore John Legters, 16, one of some 15 Woodson football players who vowed yesterday to give up drinking at least until they reach the legal drinking age. Svec was a member of the junior varsity football team.

The formation of FADD was announced at a spontaneous protest yesterday morning that drew some 250 Woodson students out of class for almost 30 minutes, with the passive approval of the school administration.

As they stood silently under the flagpole in front of the school, Todd McGregor, a member of the junior varsity football team, read a statement calling for the establishment of stricter penalties for drunk drivers.

FADD hopes to set up a "positive kind of peer pressure" to turn down alcohol, Legters said. "We'll be going to parties, and we won't be drinking. Because we're football players, most people know us . . . . they'll follow us."

"We haven't seen kids take this kind of stand before," said SADD president Kim Ritchie about the football players' resolution not to drink. "We have to begin to make it okay to say 'no' to alcohol."

The unusually powerful effect of Svec's death on his friends could be seen at his funeral service at Everly Funeral Home in Fairfax City. A somber crowd of friends overflowed from the 175-seat chapel into the hallways and adjoining sitting rooms where, red-eyed and pale in the light of old-fashioned rose lamps, they listened to the service over an intercom.

Woodson athletic director and football coach John Cox called Svec "a team player . . . everything you could ask for as a coach."

"There were bigger players, and people with more athletic talent, but nobody outworked John Svec," Cox said.

As Cox spoke, Kevin Niabati, hands clenched, recalled one football practice when Cox scolded him. "I felt like throwing my helmet at him and just saying, 'I quit.' John talked me out of it." And Niabati repeated a description of Svec that became the constant refrain of the day: "He was one of the nicest people I know."

Meanwhile, yesterday, a preliminary court hearing for Mary Ann Cronin, 34, the woman charged in connection with Svec's death, was scheduled for June 6. She has been released on $5,000 bond.

Cronin's attorney, Barry D. Murphy, said yesterday that he had not discussed the students' protests with Cronin. "My client is aware of the gravity of her action," Murphy said.