In the aftermath of the mass murder of 20 children at Connecticut's Sandy Hook Elementary School, child advocates are trying to raise awareness of the alarming rate that kids in America continue to be victims of violence, and questioning why it goes largely unreported and unrecognized by the public.

"There's so little attention paid to it and the first thing to know is those numbers are probably seriously undercounted," said Teri Covington, director of the National Center for Child Death Review. "It's been well-documented that those numbers are underreported, perhaps as high as 50 percent. Child abuse cases often don't show up on death certificates because a lot show up as injuries or accidents."

In 2011, 639 children ages 1-14 were victims of homicide, an average of 12.2 children per week nationwide, according to preliminary data from the Centers for Disease Control and Prevention. For victims ages 1-4, homicide was the third-most leading cause of death, preceded by accidents and congenital malformations; for children ages 5-14, homicide was the fifth-most common cause of death, outpaced only by accidents, malignant tumors, congenital malformations and suicide

"There's so little attention paid to it and the first thing to know is those numbers are probably seriously undercounted."

- Teri Covington, National Center for Child Death Review

Covington referred to a 2011 Government Accountability Office report on child maltreatment that found more children likely died from severe abuse or neglect than are counted by the National Child Abuse and Neglect Data System. Specifically, an estimated 1,770 U.S. children died from maltreatment in fiscal year 2009, yet nearly half of states included data only from child welfare agencies despite the fact that not all children who died from maltreatment had contact with those agencies.

"They don't get reported," Covington said. "The first part is just recognizing that it's a bigger problem than is demonstrated in the numbers. You can have something like Sandy Hook and it'll get a lot of attention initially, but then it'll fade after time."

Youth violence was a major federal priority under former U.S. Surgeon General C. Everett Coop in the 1980s, Covington said, but has largely dropped from the national conversation since that time.

"There once was a really strong emphasis on youth violence in terms of prevention rather than a criminal justice response," she said. "But there's been very little since."

Covington praised the Protect Our Kids Act, which establishes a national commission to study child fatalities and was passed by the House of Representatives last week, but noted that the effort was well underway prior to the Dec. 14 shooting that killed 26 people, including 20 children.

"It's just ironic," she said of the timing. "It's a good first step. It's the first time we've had anything at the federal level to focus on these fatalities."

Gerald Landsberg, a professor of social work at New York University and director of its Institute Against Violence, said cases of children dying occur every day in the U.S. and "most of them" are overlooked.

"Because, unfortunately, it is an unfortunately common thing," he said. "And usually the person who kills them is their parents and often the mother and father are young, have no background in child care and are often overwhelmed by circumstances in their life like poverty and find it very, very difficult to handle too much stress."

Landsberg suggested considering giving parent's educational instruction much like driver education to young adults to better equip them when becoming mothers and fathers, similar to efforts in England and France. In England, for example, any time a child is born — regardless of income — nurses are sent to the mother's home to teach her basic child-rearing skills.

"This doesn't happen here," he said.

Many child welfare agencies throughout the country are also ill-equipped to serve youth populations, he said, thanks in large part to "constant turnover" and other organizational failures.

"But often the training that many of these people get is very inadequate," he said. "So they're very unprepared to deal with the problem that they're facing and it's often the youngest child who becomes the victim."

Another venue ripe for immediate reform in the aftermath of the second-worst mass shooting in U.S. history is the country's mental health system, which is "broken," Landsberg said.

"It's especially poor for children and for adolescents," he said. "Many more children and teenagers need ongoing support."

Nationally, only 1 out of every five children and adolescents who need mental health services actually receives them, Landsberg said.

"And it's sort of illustrated by the Newtown case," he said. "Nobody followed up what happened to this young man all through his teenage years. Obviously the mother was very reluctant to get him help."

The outlook for Landsberg is a "pessimistic" one due to drastic cuts of mental health services nationwide, a trend that will continue without a seismic reversal.

"The federal government really needs to take a hard look at this to see what they can do to help," he said. "With all the emphasis that's been placed on test scores as a way to measure schools, it has detracted from looking at the social issues in [student's] lives."

Dr. Irwin Redlener, director of the National Center for Disaster Preparedness and professor of pediatrics at Columbia University, told FoxNews.com he's hopeful the Sandy Hook shooting massacre will lead to solutions of a predominately three-pronged problem of mental illness, poor parenting and the proliferation of weapons beyond those used in hunting and sport.

"There's not a lot of drama when 1 or 1.5 kids per day are killed," Redlener said. "Americans tend not to be wound up by the things that are chronic crises. What really gets our attention, unfortunately, are these horrible mass events like the shooting at Sandy Hook. But if we're smart about it, we'll let that tragedy open our eyes to a broader problem.

"The question is, what's the cause of this?"