Parkland.

On April 20, 1999, two teenage boys dressed in black trench coats went on a killing rampage at Columbine High School in suburban Denver.

The 12 students and one teacher killed in the Columbine High School shooting were remembered in a vigil on the eve of the 25th anniversary of the tragedy.

A quarter of a century after the Columbine High School shooting, the trauma from the attack has remained with survivors.

As the small Texas city of Uvalde struggles to heal after a gunman killed 19 children and two teachers at an elementary school, thoughts have also turned to making sure the school’s legacy as the place that was at the heart of a fight for the equal education of Mexican Americans over half a century ago is carried on.

The Columbine High School shooting happened on April 20, 1999 in Littleton, Colorado.

Students who were making plans to attack schools showed the same types of troubled histories as those who carried them out. The study by the Secret Service’s National Threat Assessment Center is a twist on the study of school shootings. It's a companion report to its study in 2019 on student attackers, the most comprehensive analysis of school shootings since the 1999 Columbine High School killings. One-third conducted research into previous school shootings, like the 2012 Sandy Hook Elementary School attack in Newtown, Connecticut, where 27 people, mostly first-graders, were killed. Ad“First and foremost, targeted violence is preventable if communities can identify warning signs and intervene,” Driscoll said.

On Wednesday, Reinfeld was reeling from the latest mass shooting even closer to home, after authorities say a 21-year-old gunned down shoppers at a local grocery store. “I could see at some point leaving because of all this,” said Reinfeld, a gun control activist. But it's also been haunted by shootings that have helped define the nation's decades-long struggle with mass violence. The Aurora shooting brought that terror from schools to a movie theater. After each of Colorado's biggest massacres, the local gun control movement has gained heartbroken new recruits.