Students across the country are slated to walk out of their classrooms today to demand gun control and protest against school shootings. Nearly 3,000 student demonstrations are planned from coast to coast. The walkouts are slated to last 17 minutes in honor of the 17 people—14 students and three faculty—who were killed in a mass shooting at the Marjory Stoneman Douglas High School in Parkland, Florida, one month ago today.