The massacre in Connecticut is also bringing to mind those other deadly shootings that has left a stain on American history.
The shooting at Sandy Elementary is the second-deadliest mass gun violence in U.S. history that has definitely shaken the nation. Some of the tragic moments in Newtown, Connecticut, happening days after a gunman opened fire inside a mall in Portland, Oregon. The shooter was Jacob Tyler Roberts, he killed two people and injured another before turning the gun on himself.
More violence increased over this past summer. In August, Wade Michael Page went on a shooting spree at a Wisconsin Sikh Temple. There he killed six people and exchanged gunfire with police officers. One of those officers was seriously injured and Page killed himself during the gun battle.
In July, a gunman walked in to a movie theater in Aurora, Colorado, and killed a dozen people and injured over 50 movie goers. That shooter was James Holmes. He was arrested and is awaiting trial.
In April of 2007, Seung-Hui Cho shot and killed 32 people and injured 17 others in two separate attacks at Virginia Tech University and then took his own life. That massacre is the deadliest shooting incident by a single gunman in U.S. history.
Then there's Columbine in 1999, unforgettable images of students running out of their school when their classmates, Eric Harris and Dylan Klebold, went on a killing spree. They murdered 12 students and one teacher, then the pair killed themselves.
The mass murder in Connecticut has political observers wondering whether the deaths of 20 small children will be enough to tip the debate on gun control, when other mass killings haven't.