Gary Younge of The Guardian finds that on an average day, eight children are killed in the US by guns. That's 2920 children in a year -- more than the number of people who died in the World Trade Center on 9/11. The foregoing link leads to an audio clip, in which Younge tells the stories of some of the nine children who died on a day he chose at random (November 25, 2006, Thanksgiving Sunday). One of these was a two-year-old in Tampa, FL, who found a gun behind a sofa cushion, and accidentally shot himself in the chest. On an average day, eight US children die from gunshots: four white, three black, one Hispanic; on that day, there were eight black and one Hispanic. Most are poor.
The original argument for guns in the Second Amendment, Younge notes, was self-defense against tyrannical government; today, the argument pro-gun Americans make is self-defense against each other!
Younge adds that there is very little interest in America in gun-related deaths, which are a "regular occurrence". In one case, the victim was not even named in a news report; the police never even thought to issue a press release.
Afterthought: What does it say about a culture that children's behavior with guns is even a research question?
Update: A few hours after I posted the above, I read that another two-year-old, this time in Wisconsin, has become a victim of gun violence. She is alive, but in critical condition. Why can't America make itself safe for its children?