President Obama went on to tell the victim's families they are not alone in their grief.
ABC's Mark greenblatt has more from last night's vigil, where the sobs were as audible as the speech.
"Since I have been president, this is the fourth time we have had to come together by a grieving community of a mass shooting,"says President Obama.
More than 900 people packed in to Newtown High School for an emotional interfaith service. They came to remember loved ones lost in the shootings and left with the message that those who died may help lead America to become better and safer for others.
"These tragedies must end. To end them we must change and in the coming weeks I will use the powers of this office to prevent more shootings," says President Obama.
The entire community of Newtown has transformed into one giant memorial. With flowers, teddy bears, and candles now piling up at a continuous pace, seemingly everywhere here.
"There's no way you can be living and this doesn't affect you," says a woman.
Investigators are still trying to find out what prompted 20–year old Adam Lanza to shoot his own mother multiple times in the face before continuing
his killing spree at Sandy Hook Elementary. But while this town tries to somehow begin healing. One major focus is on helping the youngest survivors find hope again, so their lives do not become defined by one moment of terror.
And the president saying tonight our entire society will be judged by how well we protect our children adding that right now we're not doing the job.
But in the coming weeks he plans to use all the powers of the President's Office in order to help make America safer.