NEWTOWN, Conn. -- An emotional President Barack Obama told an overflow crowd gathered at Newtown High School Sunday night that the nation must protect its children by facing head-on the causes he said led up to the Sandy Hook Elementary School massacre.
"We can't tolerate this any more," Obama told the crowd. "These tragedies must end. And to end them, we must change."
He said he is going to use the power of the presidency to confront the shootings that killed so many Friday morning.
"It's our first job," said Obama, referring to protecting the young. "If we don't get that right, then we won't get anything right. That is how we will be judged . . . Can we honestly say we are doing enough to keep our children, all of us, safe from harm? . . . If we are honest with ourselves, the answer is no . . . we are not doing enough and we have to change."
Obama's plea for change came about an hour after clergy members representing nearby Christian, Jewish and Islamic houses of worship led the audience in prayer and first responders to the shootings received a standing ovation as they entered the school auditorium and hugged victims' families.
Connecticut Gov. Dannel Malloy introduced the president after he told the audience that when he sees the first snowfall of winter, he will be "thinking of the 27 souls lost just a few days ago . . . we will move on, we will never forget."
The president took the stage, his expression serious and his tone compassionate.
He was not specific and did not say the word "gun" in his address, but his intentions seemed clear: He will seek change when he returns to the capital.
"No single law, no set of laws can do it. But surely we can do better than this."
Obama said he will use the power of his office to engage politicians, law enforcement and others in "an effort aimed at preventing more tragedies like this because what choice do we have? We can't accept events like this as routine. Are we really prepared to say we are powerless in the face of such carnage, that the politics is too hard?"
He said the loved ones of the 20 children and six adults struck down in the attack are joined by the nation in mourning.
Obama read the names of the 20 first-graders, between the ages of 6 and 7, who were shot multiple times by 20-year-old Adam Lanza, who earlier had shot his mother to death inside their home. Lanza killed himself at the school.
"You are not alone in your grief," Obama said. "Our world too has been torn apart."
But throughout his address, the president remained focused also on what chain of events could have helped cause the carnage.
He said, "As a nation we face some hard questions."
Being a parent, Obama said, is like having your "heart outside your body, walking around."
Obama talked about the first responders who "had a job to do" for those who needed them. He spoke of the children struck down as they went about their school routine.
"I can only hope it helps for you to know you're not alone in your grief," the president said. "Whatever measure of comfort that we can provide, we will provide."
Religious leaders from several faiths led off the vigil with prayers and calls for comfort.
Obama sat in the front row of the auditorium as the clergy members led the audience in prayer and called on a higher power for comfort.
Malloy spoke of the song "Amazing Grace" and its meaning for the "family and spouses" of shooting victims.
A rabbi sang a traditional Hebrew prayer, Christian clergy offered up spiritual reflections, and an Islamic clergy member spoke of the Quran and "God's mercy and compassion."
Other clergy urged the crowd to remember the victims and share in the grieving.
"We pray for all those who lost," the Rev. Mel Kawakami of Newtown United Methodist Church told the crowd. "Help us to care for all those in their sorrow . . . we embrace the grieving as our own."
Earlier, a crowd of hundreds slowly filed into the auditorium, which has a capacity of about 1,700. In a nearby overflow room -- a basketball gym -- sat another 1,000.
Still, others were turned away, unable to get into either building. Red Cross volunteers handed them blankets as they made their way into the cold, rainy night.
As many in the crowd left the high school in tears, Trumbull, Conn., resident Buali Naqvi said he attended because friends of his have children in the school district. He said Obama's speech was important because "he's the leader of our tribe. The whole world's looking to him. I think this was truly important."
Norwalk, Conn., resident Frank Falcone said he appreciated the unifying tone of the president's remarks.
"As a divided nation," Falcone said, "I'm sure we feel a lot more close together this season."