Today marks the 19th anniversary of the Columbine High School massacre in Littleton, Colorado, where two high school students gunned down 13 of their fellow classmates and educators. To mark the occasion, students nationwide are staging a second nationwide school walkout to honor the victims of gun violence and advocate gun control.

According to The Washington Post, Lane Murdock, a 16-year-old student at Ridgefield High School in Connecticut prompted the walkouts when he started an online petition to organize another demonstration in response to Parkland.  Unlike the last walkout which only lasted 17 minutes, today’s protest will last all day.

The Post reports this walkout is significantly smaller than the March For Our Lives protests last month, perhaps due to “a lack of promotion and questions about its goals, conflicts with mandatory standardized testing, and, in some cases, protest fatigue among students.”

Students attending schools in Colorado’s Jeffco Public Schools, sight of Columbine High School, are not participating in the walkout. The Wall Street Journal reports that officials in the school district have asked the kids not to take part in the demonstrations. “The superintendent and Columbine High School principals asked students and staff to consider service or other proactive actions instead of a walkout,” said Jeffco schools spokeswoman, Diana Wilson. Today will be a day of service for the students in this district; they will take part in projects such as cleaning up a local park and helping out at an animal shelter.

As reported earlier, one high school student was injured in another Florida school shooting this morning. The local police have apprehended the suspect and he remains in custody. David Hogg, a de facto leader of the gun control movement and survivor of the Parkland shooting, declared that the latest shooting in Ocala underscores the need for immediate action. “We have to stop this. We’re not going to be able to stop this unless we continue to make our voices heard, though, when our elected officials won’t,” Hogg argued on social media. “We have to get out there and make our voices heard, not as Democrats or Republicans, but as Americans.”