Twenty-six people, including 20 children, were killed when a man opened fire inside the school.
Hours after the shooting, a tearful Obama said he grieved first as a father. In those remarks and later in his Saturday radio address, Obama called for "meaningful action" to prevent such shootings, but did not say what it should be.
Obama's visit to Newtown for an interfaith vigil would be the fourth time he has traveled to a city after a mass shooting.
The president had planned to travel to Maine on Wednesday for an event promoting his positions in "fiscal cliff" negotiations, but the White House canceled that trip because of the shooting.
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