It's a tragically familiar story: In June, a 3-year-old boy in Hamilton, Ohio, went through his mother's purse, pulled out a gun, and fatally shot himself in the chest while playing with the firearm. The 911 call that followed was simply horrifying: "My son just shot himself, and I'm not getting a pulse," his mom said. "Oh, my God. Oh, my God. I'm not getting a pulse. … I don't think he's alive!"

A new study suggests something like this happens quite often in the US: 110 American children ages 0 to 14 die in accidental shootings each year. What's worse, the researchers found this estimate was 80 percent higher than federal data from the National Vital Statistics System previously suggested. So not only do these tragedies happen quite often, but oftentimes the federal data doesn't even pick up on the accidents.

Using data from the National Violent Death Reporting System on unintentional firearm deaths for children ages 0 to 14, researchers David Hemenway and Sara Solnick looked at 16 states from 2005 to 2012 and extrapolated their findings to the entire US. (This, researchers note, is the study's biggest weakness: The system doesn't have data for all 50 states, but the 16 analyzed states varied in demographics and appeared to be fairly representative of the US as a whole.)

The study found the victims of gun accidents were boys 81 percent of the time. In about two-thirds of cases, the victim was shot by someone else. In those cases, 97 percent of the time the shooter was male. And more than 90 percent of the time, the shooter was family or a friend. About 19 percent of victims were shot in the homes of friends, and 11 percent of deaths involved hunting. It was very rare for an adult who's not a family member to be accidentally shot by or accidentally shoot a child.

Time and time again, the shootings followed a similar pattern: A child found a parent's stray gun, played with it, and accidentally fired it, killing himself or a bystander. It's an absolute tragedy, one that could be easily prevented if firearms were stored more safely.

But it's also the type of tragedy that's much more likely to happen in the US. Since these accidents require stray guns to be around, and Americans are much more likely than people in other developed nations to own guns, American kids are much more likely to accidentally shoot and kill themselves.

These deaths are way more common in the US, because the US has way more guns

Like all gun violence, kids accidentally shooting themselves is a much bigger problem in the US compared with its developed peers around the world. A 2011 study co-authored by Hemenway, who heads the Harvard Injury Control Research Center, found that in the US, unintentional firearm death rates of children ages 0 to 14 are about 10 times higher than in other developed countries.

People tend to believe that having a firearm on themselves or in their homes will protect them. But the research shows this isn't the case: Living in a house with a gun actually increases a person's odds of an early death. Looking at the evidence, the American Academy of Pediatrics concluded, "The absence of guns from children's homes and communities is the most reliable and effective measure to prevent firearm-related injuries in children and adolescents."

But Americans are among the least likely people to follow this advice in the developed world. Americans make up about 4.43 percent of the world's population, yet own roughly 42 percent of all the world's privately held firearms. And the US has the highest number of privately owned guns in the world: Estimated in 2007, the number of civilian-owned firearms in the US was 88.8 guns per 100 people. The world's second-ranked country was Yemen, a quasi-failed state torn by civil war, where there were 54.8 guns per 100 people.

The empirical research suggests this leads to tens of thousands of unnecessary deaths each year, because more guns mean more gun deaths. Researchers have found this is true not just with accidents, but also homicides, suicides, domestic violence, and even violence against police. To deal with those problems, America will have to not only make guns less accessible, but likely reduce the number of guns in the US as well.

Many American may look at these numbers and still believe that more restrictive gun laws — like those that require guns to be safely stored — are a bad idea, and gun rights are worth protecting. But the research suggests that these beliefs come at a deadly cost — and for parents, the statistics should invite caution when they consider placing kids in environments with firearms.