In a wave of demonstrations reaching from Arizona to Maine, students at dozens of U.S. high schools walked out of class Wednesday to protest gun violence and honor the victims of last week’s deadly shooting in Florida.

The protests spread from school to school as students shared plans for their demonstrations over social media. Many lasted 17 minutes in honor of the 17 people killed at Marjory Stoneman Douglas High School in Parkland.

Hundreds of students from Maryland schools left class to rally at the U.S. Capitol. Hundreds more filed out of their schools in cities from Chicago to Pittsburgh to Austin, Texas, often at the lunch hour. Thousands walked out in Florida.

At the protest in Washington, students held a moment of silence in memory of those killed in Parkland and listened as the names of the dead were recited. Daniel Gelillo, a senior at Richard Montgomery High in Rockville, Maryland, helped organize the protest and said students aimed to pressure lawmakers to act on gun control.

“The Orlando shooting, Las Vegas and now Parkland,” he said. “Something has to happen. Innocent people are dying because of the easy access to firearms in this country.”

While some students said their opinions have been belittled because they’re still teenagers, they counter that they’ll soon be voters and shouldn’t be taken lightly. Some said they’re taking a stand because lawmakers haven’t.

“They send out their thoughts and their prayers, and we appreciate that, but that’s enough,” said Warren, of Dublin Scioto. “We need change.”

The Florida high school shooter’s lawyer has said he is sad, mournful and remorseful and has called him “a broken human being.”