With words of hope and healing, Coloradans on Monday marked the 10th anniversary of the Columbine High School shootings that left 12 students and a teacher dead. Flags flew at half-staff over the school in the south Denver suburbs, and dozens of mourners lay roses and carnations at a nearby memorial. About 70 people gathered outside the state Capitol in Denver to push for gun control, while lawmakers inside passed a resolution honoring the victims. "Columbine will not become just a metaphor for tragedy," Rep. Ken Summers told lawmakers before they passed a resolution called "Triumph Over Tragedy." Summers was a pastor in the Columbine neighborhood when the shootings occurred. Two seniors at Columbine unleashed an attack with guns and pipe bombs on the morning of April 20, 1999. A bigger bomb, which they hoped would destroy the crowded cafeteria, failed to go off. The gunmen, Eric Harris, 18, and Dylan Klebold, 17, committed suicide. Silent mourners streamed by to pay their respects at the Columbine Memorial on a hill in Clement Park overlooking the school. Many wiped away tears, and some sat with eyes closed in silent reflection at the memorial's fountain. Roses in every color were placed on tablets memorializing the victims. Some people left unlit votive candles or tied handwritten notes with ribbons to flowers. "I just felt I had to be here today," said Kelsey Snyder, 23, who was in eighth grade at a Denver school when the massacre happened. "I was just scared senseless because none of us could understand why anyone would do this," she said. Columbine called off classes Monday, as it has every year that the anniversary falls on a school day. A police patrol car idled out front. A private breakfast was held at the school for members of the class of 1999, said Lynn Setzer, spokeswoman for Jefferson County Public Schools. She had no details on the breakfast or turnout. At the gun control rally at the Capitol, Tom Mauser, father of Columbine victim Daniel Mauser, said the shooters did not kill the victims' spirits, and "they did not kill our spirits either." Thirteen people with ribbons in school colors white and blue wrapped around their necks lay on the at the foot of the Capitol steps to represent the victims and 23 others representing the wounded encircled them. Andrew Goddard of Richmond, Va., whose son Colin was wounded at the Virginia Tech University massacre two years ago, also attended the rally. He said new police tactics that emerged after Columbine probably saved his son's life. "They (Columbine victims) paid a huge price for that small lesson, but that lesson did benefit the students at Virgina Tech," he said. At Columbine, police and deputies followed a standard tactic of establishing a perimeter before advancing carefully toward a gunman. Afterward, many agencies adopted a new policy of aggressively attacking the shooter. Virginia Tech student Seung Hui-Cho killed 32 people and committed suicide on April 16, 2007. On the anniversary, Oprah Winfrey canceled an episode schedule to air Monday, "10 Years Later: The Truth about Columbine." Winfrey posted a message Monday morning on her Facebook page, saying that after she reviewed the taped show, she decided to pull it because of its focus on the two gunmen. She urged viewers to keep the Columbine community in their thoughts. Gov. Bill Ritter had planned to address the Legislature in the House chamber Monday, but his speech was canceled at the last minute because House Speaker Terrance Carroll declined to suspend the rules. "Traditionally, the governor doesn't come on the floor unless it's the State of the State speech, and I'm not inclined to change that precedent," said Carroll. Both Carroll and Ritter are Democrats.The Columbine anniversary memorial observance will take place at the Clement Park Amphitheater, 7306 W. Bowels Ave., located in Clement Park, adjacent to Columbine High School.