Sandbox by Mandy Collins-Moore (Book Series)

From the Rise Universe, the adventure that began in Rise now continues with Sandbox.

When he founded Sandbox, people thought it was a novel idea. When he fortified it, they thought he was eccentric. When he talked about a worldwide catastrophe, they said he was crazy. Now Sandbox may be the last safe place on Earth. Can they keep it that way, or will Sandbox fall? How will JC, Capp, & company deal with the challenges thrown at them, from both the afflicted & the living?