Jeff Vespa

As part of a social media initiative called #whatif, photojournalist Jeff Vespa captured students' heart-wrenching tales of survival — and their determination to create a future free of gun violence

The 18-year-old senior worried immediately about her 14-year-old sibling, telling her mom, "I'm safe, take care of my sister"

The 15-year-old freshman survivor is helping to raise scholarship funds to honor her soccer teammate and shooting victim Alyssa Alhadeff

The 17-year-old junior texted her mom to say she didn't know if she'd survive the shooting and empathizes with parents whose children did not

The 14-year-old freshman found comfort in her uncertain panic that if she died, she'd be surrounded by friends

The junior, 17, says bonds among friends have strengthened as they move together through vigils and memorials to activism

Maddie Gaffney, 17, says her friend Luke Hoyer's mom searched for hours before learning the 15-year-old freshman was among those killed in the mass shooting

Lizzie Eaton, 16, hid in a classroom as she awaited rescue from the overheard gunshots

Marjory Stoneman Douglas Shooting student Sam Schneider was scared to text his sister to find out whether she survived the mass shooting there last month

Maddie Gaffney, 17, says her friend Luke Hoyer's mom searched for hours before learning the 15-year-old freshman was among those killed in the mass shooting

Lizzie Eaton, 16, hid in a classroom as she awaited rescue from the overheard gunshots

Marjory Stoneman Douglas Shooting student Sam Schneider was scared to text his sister to find out whether she survived the mass shooting there last month

"My heart aches 17 times for our coaches, teachers, siblings that we have to bury," says Leal, 16

"It has to be our generation that says, 'No, we are not going to take this anymore,' " says Hogg, 17

"When you're hearing gunshots, all you can think about is — 'I'm next,' " says Hebron, 14

"With about 20 minutes of class left, I heard the first shots that I've ever heard in my life of a gun," says survivor Kraemer, 17