Updated March 25

Carrying hand-drawn signs as they marched in Pittsburgh’s March for our Lives, children — some barely old enough to pronounce the words — chanted “save our kids.”

Teenagers, meanwhile, screamed the chant, filling the air between Downtown skyscrapers with their words, calling on their leaders to protect Americans with gun safety laws.

Two local students, sisters Erin and Emma Simard of Shadyside Academy, organized the rally of 30,000 marchers. It was one of hundreds of rallies held in conjunction with a national march in Washington, D.C., organized by students at Marjory Stoneman Douglas High School in Parkland, Fla., after a gunman killed 17 people there in February.

Chants included: “No more stalling, no more lives, pass a bill and save our lives;” “Hey hey NRA, how many kids have you killed today?;” “Students marching one by one, we want schools safe from guns;” “Gun control is a must. We want leaders we can trust.”

Teachers and hundreds of other adults marched alongside the students, their signs mimicking their chants — all demanding action.

Here’s what the students demanded.

This article has been updated with a more recent crowd estimate.