Thousands of students nationwide walked out of their schools Wednesday in protest of gun violence.

The walkout was in response to the Valentine's Day mass shooting that killed 17 people at Marjory Stoneman Douglas High School in Parkland, Florida.

At 10 a.m. Wednesday, students closed their textbooks and walked out of class, with 17 minutes marking each life taken in Florida.

"We're showing Congress and we're showing politicians that we care about gun violence," said Duncan Freeman, of Bronx Science High School. "And we care that we want to end it, and we want our schools to be safe for everyone."

In response, House Speaker Paul Ryan posted a video on his Twitter page with the caption: "Tragic violence has no place in our schools. Today, the House will take concrete action to prevent this violence through the bipartisan STOP School Violence Act."

In New York City, Mayor Bill de Blasio joined students at Edward R. Murrow High School in Brooklyn.

"We need you -- we need your leadership," he said. "You have shown the kind of leadership that I have never seen before. And I am certain that change is coming because of you."