These teens are channelling their fear and anger to push for change in a country that has resisted implementing any gun control despite hundreds of mass shootings.
While the shooter was still raging around the school with an assault weapon, one student, an aspiring journalist, decided he would spend what could have been his last moments documenting his classmates' fear.
David Hogg, 17, told CNN that despite the "sheer terror" of that moment, he recognised it as one that needed documenting - if not for him to report, then for survivors and lawmakers to understand how desperately the country needs to implement reforms to prevent yet another mass shooting.
He started interviewing students in the cramped closet they were hiding in, who told him how terrified they felt.
Since the shooting last Wednesday, students have organised a demonstration in Washington next month called March for Our Lives.
One of five core organisers, Emma Gonzalez, 18, told the New York Times they wanted the violence to stop.
"We are protecting guns more than people," she told the paper. "We are not trying to take people's guns away; we are trying to make sure we have gun safety."
It could be that these teenagers manage what adults before them have failed to do - convince American politicians to enact some form of gun control.
These teens have real courage.
