Thousands of students across the United States walked out of their classrooms and into the nation’s schoolyards and streets on Friday in a renewed, coordinated protest against gun violence.

The demonstrations, from the statehouse in Texas to a Chicago park, coincided with the 19th anniversary of the mass shooting at Colorado’s Columbine High School — a rampage that stirs students still, even though it happened before most of today’s high school students were born.

Friday’s walkout was the third nationally organized student protest in the two months since 17 people were shot and killed at Marjory Stoneman Douglas High School in Parkland, Fla. Students walked out of classes in March and held rallies across the country later in the month. They say that elected officials have not done enough to prevent school shootings despite a yearslong national debate and the grim roll call of campus killings since Columbine.

Shortly before the walkout on Friday began, at 10 a.m., another Florida high school was the site of a shooting when a 19-year-old man entered Forest High School in Ocala and shot a 17-year-old student before being apprehended by an officer stationed at the school. The victim was expected to survive.