Saturday marked one year since 20 students and six adults were killed at Sandy Hook Elementary School in Newtown, and this week's shooting at a high school in Centennial, Colo., stirred up fresh concerns about gun violence nationwide.
"We were horrified to hear today of a school shooting ... just one day before the one-year mark of the Sandy Hook shootings," the citizens group Sandy Hook Promise said in a written statement this weekend. "It's time to start a new conversation to protect our children."
One person was seriously wounded in Centennial on Friday by a teenage gunman who then killed himself.
President Obama also touched on the volatile issue of gun control in his weekly radio address, saying Newtown had kept the matter from being shunted to the sidelines in Washington. "Over the past year, their voices have sustained us," he said.
In Connecticut, the remembrances revolved around the chiming of church bells. Bells rang 26 times for the 26 victims as snow fell across the state.
The Los Angeles Times said the Newtown officials had asked spectators and the national media to stay away on Saturday out of respect for the town's privacy and still-emotional state. Some parents who lost kids in the shooting spree posted messages and videos on the Internet to express their grief and eulogize their children.
Celebrity Families of 2014 [PHOTOS]