He didn't know the gun was loaded.
The 14-year-old Massachusetts boy had recently found his mother's handgun, which she kept hidden under her mattress for protection.
"Promise me you'll never touch it," his mother, a single mom, had asked him.
But the lure of the gun was irresistible. He decided to show it off to his neighbor, 12-year-old Brian Crowell.
"He was going, 'Click, click, click,'" pretending to shoot the gun, says Brian's mother, Ann Marie Crowell, who spoke to the child and his mother after the incident. "But there was one last bullet. It went into Brian's neck."
And just like that, Crowell's son was gone.
Nearly 800 children under 14 were killed in gun accidents from 1999 to 2010, according to the Centers for Disease Control and Prevention. Nearly one in five injury-related deaths in children and adolescents involve firearms.
Although mass shootings get more attention, children are far more likely to be killed at home.
Through homicide, suicide and accidents, guns cause twice as many deaths in young people as cancer, five times as many as heart disease and 15 times as many as infections, according to the American Academy of Pediatrics.
And while Congress voted down gun legislation last month, children's advocates such as Crowell are urging parents and communities to take their own steps to protect kids.
Crowell, who attended the State of the Union address in January as President Obama's guest, has devoted her life to gun safety, urging parents to ask whether there are guns in the home before sending their kids for playdates.
"I had never thought to ask about guns in the home," says Crowell, of Saugus, Mass.
Saugus says she's aiming for common sense, not sweeping political change. Nearly 40% of American households have guns, studies show.
"If I owned a gun, I wouldn't be mad that someone asked," Crowell says. "If you were going over for a playdate to a house with a swimming pool, wouldn't you want them to lock the pool gate? As a parent, you want to do anything you need to do to protect your child."
The American Academy of Pediatrics recommends that pediatricians include a question about guns in the home when taking a patient's history.
"It's no different than when we ask about safety seats in the car or bicycle helmets, or the temperature of your hot water heater," academy president Thomas McInerny says. "We want to keep children safe. And most parents say they appreciate it."
If a child's parents own guns, pediatricians should counsel them about the need to store them safely, the academy says. Its policy statement on guns says, "The safest home for a child or adolescent is one without firearms."
Research shows that storing guns locked and unloaded reduces the risk of both injuries and suicide by about 70%, according to a 2005 study in the Journal of the American Medical Association.
Bill Brassard, a spokesman for the National Shooting Sports Foundation, says, "Safe storage is absolutely critical to preventing the misuse of firearms."
People who want quick access to a gun for security can still store them safely, Brassard says, with lockable boxes that can be opened with a keypad. Most major firearm manufacturers now include a gun lock with new guns, Brassard says.
Yet many fail to follow such advice.
About 29% of households with children under 12 fail to lock up their guns, according to a 2006 study in Archives of Pediatrics and Adolescent Medicine by Harvard's David Hemenway and others.
Some see the pediatrics academy's policy as a threat to gun owners' rights.
In the past two years, six states have considered bills to prevent doctors from asking about guns in the home or recording that information into medical records. Only Florida's bill passed. That law never went into effect, however, because it was blocked by a judge.
Some of the USA's largest firearms organizations run gun safety programs.
The National Shooting Sports Foundation says its 12-year-old ChildSafe program has distributed 35 million free firearm safety kits that include a gun locking device and firearm safety brochure.
National Rifle Association spokesman Andrew Arulanandam says 18 million children have participated in the NRA's Eddie Eagle GunSafe Program. The program teaches kids, "If you see a gun, STOP! Don't Touch. Leave the Area. Tell an Adult."
"The one thing we always recommend is education," Arulanandam said. "You have to teach your children that guns aren't toys."
Arulanandam notes that gun deaths among adolescents have fallen sharply. In 1994, the rate of all firearms-related deaths in teens 15 to 19 years old peaked at 28 deaths per 100,000 people. Declining homicide rates helped lower that rate to 11 deaths per 100,000 people in 2009, according to the CDC.
Fewer children are dying from gun accidents today than a decade ago, as well. The number of kids under 14 who died in a gun accident fell from 86 in 2000 to 62 in 2010, according to the CDC. Yet progress has been uneven. Among the youngest children -- those under age 4 -- the number of accidental gun deaths more than doubled, to 25 a year in 2010.
Arulanandam credits programs like Eddie Eagle for helping to reduce deaths in children. Yet Arthur Kellermann, a policy analyst at Rand Corp., said programs such as Eddie Eagle have never been independently assessed to measure whether they really make kids safer. He worries that gun safety programs could give parents a false sense of security.
Most parents believe their child is smart enough not to touch a gun, surveys show. Studies prove them wrong, Kellermann said.
In an experiment in which researchers observed how 8- to 12-year-old boys behaved when left alone in a room with a hidden gun, 75% of boys found the gun within 15 minutes. Only one of 64 kids in the experiment left the room to notify an adult. The gun was modified so it couldn't fire.
Of the boys who found the gun, 63% handled it and 33% pulled the trigger.
More than 90% of boys who handled the gun or pulled the trigger said they had received some sort of gun safety instruction, says Kellermann, co-author of the study, published in Pediatrics in 2001.
"Although I have no doubt that the (NRA) program is well intended, I worry that it may foster a sense of complacency among gun-owning parents, that it's OK to keep a gun loaded and readily available for protection because their child will respect it," Kellermann says. "Even kids who've been taught gun safety are naturally curious."
Guns also should be designed more safely, Kellermann says.
If manufacturers can make childproof aspirin bottles, they should be able to make a gun that can't be operated by a child, says Hemenway, director of the Harvard Injury Control Research Center.
Guns also should be redesigned so that they don't go off accidentally when dropped, Hemenway says.
"What I don't understand is why the industry hasn't done more to make handguns childproof, since we have no evidence to date that it is possible to make children gun-proof," Kellermann says. "And as recent tragedies have proven, they are not bullet-proof."