The scene in the White House briefing room was one of the most emotional moments of Obama's presidency. Near him, two senior aides cried and held hands as they listened to the president.
Twenty-seven people, including 20 children, were killed when a gunman opened fire inside the school. The shooter blasted his way through the building as young students cowered helplessly. The dead included the shooter.
The story jolted parents and other people across the nation, and the White House was no different.
Obama began his comments with no greeting. He ended them with words of Scripture, walking away in silence.
He recited the future milestones lost, and had to pause again to gather his words.
"They had their entire lives ahead of them birthdays, graduations, weddings, kids of their own," the president said of those who were killed.
He ordered that U.S. flags be flown at half-staff on public grounds through Tuesday. The White House also canceled a trip Obama was planning to take Wednesday to Portland, Maine.
As the president received briefings about the shooting, his spokesman, Jay Carney, responded to questions about gun control and Obama's campaign promises on the matter by saying "I don't think today is that day" for such a discussion.
Others, however, said it was.
"If now is not the time to have a serious discussion about gun control and the epidemic of gun violence plaguing our society, I don't know when is," Rep. Jerrold Nadler, D-N.Y. said in a statement.
The president himself signaled a desire for action, but he was not specific.
"As a country, we have been through this too many times," Obama said. "We're going to have to come together and take meaningful action to prevent more tragedies like this, regardless of the politics."
During Obama's time in office, mass shootings have shaken communities in Wisconsin, Texas and Colorado.
The latest attack comes less than two weeks before Christmas. It appeared to be the nation's second-deadliest school shooting, exceeded only by the Virginia Tech massacre in 2007.
Obama spoke from the "James S. Brady Press Briefing Room," named in 2000 in honor of the former White House press secretary, James Brady, who was shot and disabled in the assassination attempt on Ronald Reagan in 1981. Brady and his wife, Sarah, have become activists for gun control.
The president and his wife, Michelle, have two daughters.
"Michelle and I will do what I know every parent in America will do, which is hug our children a little tighter," he said. "But there are families in Connecticut who cannot do that tonight, and they need all us of right now."
The president pledged support to Connecticut Gov. Dannel P. Malloy.
Said Obama: "He will have every single resource that he needs to investigate this heinous crime." Obama statement after Connecticut school shooting
Text of President Barack Obama's address to the nation after Friday's mass shooting at a Connecticut elementary school, as provided by CQ Transcriptions:
"This afternoon, I spoke with Governor Malloy and FBI Director Mueller. I offered Gov. Malloy my condolences on behalf of the nation and made it clear he will have every single resource that he needs to investigate this heinous crime, care for the victims, counsel their families."
"We've endured too many of these tragedies in the past few years. And each time I learn the news, I react not as a president, but as anybody else would as a parent. And that was especially true today. I know there's not a parent in America who doesn't feel the same overwhelming grief that I do."
"The majority of those who died today were children beautiful, little kids between the ages of 5 and 10 years old. They had their entire lives ahead of them birthdays, graduations, weddings, kids of their own. Among the fallen were also teachers, men and women who devoted their lives to helping our children fulfill their dreams."
"So our hearts are broken today for the parents and grandparents, sisters and brothers of these little children, and for the families of the adults who were lost."
"Our hearts are broken for the parents of the survivors, as well, for as blessed as they are to have their children home tonight, they know that their children's innocence has been torn away from them too early and there are no words that will ease their pain."
"As a country, we have been through this too many times. Whether it is an elementary school in Newtown, or a shopping mall in Oregon, or a temple in Wisconsin, or a movie theater in Aurora, or a street corner in Chicago, these neighborhoods are our neighborhoods and these children are our children. And we're going to have to come together and take meaningful action to prevent more tragedies like this, regardless of the politics."
"This evening, Michelle and I will do what I know every parent in America will do, which is hug our children a little tighter, and we'll tell them that we love them, and we'll remind each other how deeply we love one another. But there are families in Connecticut who cannot do that tonight, and they need all of us right now. In the hard days to come, that community needs us to be at our best as Americans, and I will do everything in my power as president to help, because while nothing can fill the space of a lost child or loved one, all of us can extend a hand to those in need, to remind them that we are there for them, that we are praying for them, that the love they felt for those they lost endures not just in their memories, but also in ours."
"May God bless the memory of the victims and, in the words of Scripture, heal the brokenhearted and bind up their wounds."