THE FIGHT AGAINST GUN VIOLENCE.

P.J. Young was home watching TV on a summer afternoon when his mother called and told him to come to the hospital right away.

He leapt on his bicycle and pedaled as fast as he could. "All these wild thoughts raced through my head," P.J. recalls. "I thought maybe one of my older brothers had gotten into an accident and broken a leg or an arm."

The news was much worse. His 19-year-old brother, Andrew, was dead. He had been sitting in a car at a stoplight, on his way home for dinner, when he was shot through the heart. Andrew's twin brother, Sam, also a passenger in the car, had cradled his dying brother's head as they raced to the hospital.

The shooter was an 18-year-old boy on a bicycle. He had been ordered to kill somebody as part of a gang initiation and just happened to pick Andrew. The boy was caught and is serving a 40-year prison sentence.

For the Youngs, the June 1996 murder has forever changed their lives. They still keep one empty chair at their dinner table.

"It has made me a madder person," says P.J., now 16. "I'll have these flashbacks. Sometimes it's just a little tap, sometimes it's a hard hit."

The Youngs are just one of the more than 30,000 American families who suffer the loss of gun-related deaths every year. Often, gun violence is a tragedy in which young people play a starring role--both as perpetrators and victims.

The numbers are alarming: For people ages 15 to 19, firearm injuries are the second-leading cause of death, right after car accidents. Last spring, panic over gun violence peaked with a flurry of schoolyard shootings. In nine separate incidents, young people opened fire on teachers and classmates, killing 15 people and wounding dozens.

Public outrage over the killings moved the country to action. The solutions range from gun control and police crackdowns to tougher sentences and community outreach. Almost every proposal is controversial and the debates have been emotional.

The good news is that something is working. The latest statistics show that gun violence has declined since hitting an all-time high in 1993 (see THE TURNING TIDE).

The bad news is the cost of violence remains unacceptably high.

Here's a look at what's happening in the war on gun violence, with reports from several fronts.

GUN-CONTROL LAWS: The U.S. has more guns per person in private hands than any other country--more than 235 million according to some estimates.

Advocates of gun control have proposed toughening safety regulations on handguns, holding gun owners responsible if their child gets hold of a gun, and prohibiting individuals from buying more than one gun a month.

SUING GUN MAKERS: Six cities, including Chicago and New Orleans, are suing the gun industry, arguing that gun manufacturers should reimburse them for the costs of gun violence, including medical care and policing.

Gun makers argue that they should not be held responsible when people misuse their products. Such lawsuits unfairly shift the blame for crime away from the criminals, they say.

SCHOOL SECURITY: Even though a student's chances of being killed at school are one in a million, school districts across the country are installing metal detectors, alarms, and video cameras. And they're hiring more security guards and searching school lockers. Electronic ID cards are on the way.

While the attention to gun violence is encouraging, it comes as too little, too late for families like the Youngs.

"Parents who have lost a child to homicide realize it's the worst thing that can happen," says Steve Young, Andrew's father. "Emotionally, the movement of the country is with us."

RELATED ARTICLE: THE TURNING TIDE

SMARTER TEENS BEAT THE ODDS

Just a few years ago, crime experts were predicting the emergence of a new wave of violent teenagers called "super-predators." This generation of teenage thugs was expected to make the crime wave of the late 1980s look like a day at the beach.

It didn't happen.

In fact, gun violence peaked in 1993 and has declined steadily since then. The rate of murders committed by 14-to 17-year-olds has fallen by nearly half.

"The coming storm of juvenile violence is more science fiction than social science," admits Franklin E. Zimring, one of the experts who had predicted the crime wave.

WHAT HAPPENED?

The experts were relying on population trends. Historically, teenagers commit a lot of crime. The number of teenagers is increasing. So, they thought, more teenagers means more crime.

That didn't happen for several reasons: The use of crack cocaine has declined. Police departments around the country have clamped down on juveniles with guns. And, say some criminologists, today's teenagers are just smarter about the costs and benefits of crime.

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For related articles about gun violence from The New York Times, and a list of web sites on the topic, see the UPFRONT web site, http://www.nytimes.com/upfrout