Students, teachers, survivors and hundreds of thousands of other people took to the streets by National Mall to demand changes to the nation's gun control laws in one of the largest student-led protests since the Vietnam War. Metro recorded more than 300,000 riders, more than double what they'd normally get on a Saturday.
Hundreds of thousands of people converged in D.C. Saturday for the March for Our Lives rally against shootings and gun violence in schools. See photos.
In countries around the world, people switched off their lights for Earth Hour, a global call for international unity on the importance of addressing climate change.