Run, Hide, Fight Back by April Henry 

When a deadly shooting breaks out in a Portland shopping mall, a diverse group of teens ends up trapped behind a store’s security shutter. To her own surprise, seventeen-year-old Miranda finds the others looking to her as their leader. But she’s hiding a big secret—and she’s not the only one. The group has only three choices: Run, hide, or fight back. The wrong decision will have fatal consequences.