As class dismissed before 10 a.m. Friday morning, the Shawnee Mission West students made their way out the back of the building, streaming onto the practice field.

At first there were dozens. Soon there were hundreds. And they were gathered for a common purpose: To say that it was time for action to end school shootings in America.

During a 17-minute rally — one minute for each of the victims of the Parkland, Fla., shooting — the students addressed the need for kindness and compassion for one another, the destigmatizing of mental health issues, and the need for reform to gun control laws.

Senior Thea Kinner told her classmates that they had an obligation to keep pushing for the world they wanted to see.

“Go from here — become the leaders that this country not only needs but deserves,” she said. “And if nothing else, if you choose not to be a leader yourself, well then go vote like one. It is our duty, not ours alone, but ours together, to dig ourselves out of the hole put in place by our predecessors.”

We’ve got full video of the walkout demonstration below: