Like a teacher reading the roster before class, US President Barack Obama Sunday sketched in haunting, human terms, the horror of the Connecticut school massacre.

"Charlotte, Daniel, Olivia, Josephine, Ana, Dylan, Madeline, Catherine, Chase, Jesse, James, Grace, Emilie, Jack, Noah, Caroline, Jessica, Benjamin, Avielle, Allison, God has called them all home."

Deep, heartrending sobs broke the silence at a harrowing vigil service, as Obama voiced the names of 20 kids -- aged six and seven -- shot multiple times in their classrooms Friday by a crazed gunman.

Obama, called for the fourth time in his presidency to eulogize the dead of a mass gun crime, sought to offer solace to parents suffering unimaginable loss, as well as hints of a push for gun control reform.

Anguished moans from relatives also split the hush as Obama lauded six heroic teachers and support staff who sacrificed themselves trying to halt gunman Adam Lanza's rampage at Sandy Hook elementary school.

"Dawn Hocksprung and Mary Sherlach, Vicki Soto, Lauren Russeau, Rachel Davino and Anne Marie Murphy.

"They responded as we all hope we might respond in such terrifying circumstances, with courage and with love, giving their lives to protect the children in their care."

Many eyes in the audience glistened with tears as Obama spoke, and -- as a father of young girls and as a president -- seemingly second guessed himself over his failure to do more to stiffen federal gun laws.

"This is our first task, caring for our children. It's our first job. If we don't get that right, we don't get anything right. That's how, as a society, we will be judged," Obama said.

"And by that measure, can we truly say, as a nation, that we're meeting our obligations?

"Can we honestly say that we're doing enough to keep our children, all of them, safe from harm?" Obama asked in stark, powerful language.

Obama appeared to commit himself to a genuine effort to reform firearms laws, perhaps by leading a push to restore a ban on assault weapons like the one used by Lanza, which expired in 2004.

In his speech at the high school in picturesque Newtown, close to the cursed elementary school, Obama did not mention gun control directly, though his intent appeared clear.

He did not cast the fight against the entrenched gun lobby, which wields substantial power in Congress, as an effort to confiscate weapons -- a desire his most vehement conservative opponents often say he harbors.

But he suggested that the argument should be built more on the need to protect, innocent, defenseless children.

Obama's vow may herald a push for laws governing, and restricting, ownership and use of powerful guns and rapid-fire ammunition.

Any such legislation would need to avoid falling foul of the right to bear arms enshrined in the US constitution. But the newly re-elected president questioned whether the freedom to have a gun could be allowed to constrain the right of others to live in "happiness and with purpose."

"Are we really prepared to say that we're powerless in the face of such carnage, that the politics are too hard?

"Are we prepared to say that such violence visited on our children year after year after year is somehow the price of our freedom?"

To effect change, Obama will have to conquer what critics see as one of the flaws of his first term: he has often proven more adept at defining a problem rhetorically than in building a political coalition to fix it.

Obama at least is no longer beholden to rural, white, gun-owning voters in states like Ohio, Pennsylvania or Colorado, after his re-election victory last month.

But many Democratic lawmakers Obama would need for a concerted push on guns do not enjoy the political freedom that the second term president will enjoy.

Perhaps that is why Obama did not specifically mention guns, but cast the fight ahead as part of a nation's fundamental duty to protect its young.

"We know we're always doing right when we're taking care of them, when we're teaching them well, when we're showing acts of kindness. We don't go wrong when we do that," Obama said.