A boy looks through the fence at the Columbine High School tennis courts in Littleton, Colo., days after the April 20, 1999 shootings.

(AP Photo/Eric Gay)

Survivors of the school shooting in Parkland, Florida are expected to be in Colorado Thursday to take part in what's being called "Vote for Our Lives." It will take place near Columbine High School to help mark the 19th anniversary of the Columbine mass shooting.

Journalist Dave Cullen wrote a book about Columbine, and this year he's been in Florida writing for Vanity Fair about the shooting at Marjory Stoneman Douglas High School. He tells Colorado Matters where he sees the connections between the two events -- and what’s different.

As the Associated Press reported after the Florida shooting, administrators there reached out to former Columbine principal Frank DeAngelis for advice, since there is no book to teach what he learned after gunmen killed 12 of his students and a teacher on April 20, 1999.

Thursday's event aims to get students to become politically active. Since the shooting, Stoneman Douglas students have organized walkouts nationwide, and Columbine students have taken part. References to Columbine were also a big part of the national March For Our Lives protest last month in Denver and other Colorado locations.