Newtown, Connecticut (CNN) -- "We can't tolerate this anymore." That's what President Barack Obama told those attending a memorial service Sunday in Newtown, Connecticut, two days after a man shot his way into Sandy Hook Elementary School and killed 26 people -- 20 of them children no older than 7, who would never go on a date, drive a car, marry or have kids of their own. Obama offered his condolences, saying, "All across this land of ours, we have wept with you." He praised the residents of Newtown for having pulled together and "loved one another" with a spirit all could emulate. And he asked whether more could be done to prevent more parents, sisters and brothers, like those in this quiet New England town, from suffering similar heartaches.
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NEW: "These tragedies must end. And to end them, we must change," Obama says
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NEW: He vows action, saying America must do more to protect its children
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NEW: The mother of a teacher being hailed as a hero calls her daughter "selfless"
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All victims at the Sandy Hook school were shot multiple times, a medical examiner says
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The nightmare got worse as he moved through @placeholder's halls.