Students across the United States walked out of class to protest against gun violence on Friday, April 20, the 19th anniversary of the Columbine High School shooting.

Students were to walk out at 10am and hold a moment of silence for 13 minutes – a minute for each victim of the shooting.

A similar walkout event was held in March, one month after the Parkland shooting, to protest gun violence.

At James Madison Memorial High School in Madison, Wisconsin, students created a memorial with the names of those who were killed by gun violence in the first week of 2018, as shown in this video. The names of the Columbine victims also were included in the memorial. Students laid flowers at the memorial and a moment of silence was held for 13 minutes during the walkout. Credit: _sophieguthier via Storyful