Fire-us #2: The Keepers of the Flame (Fire-Us Trilogy)

They have found others.

Five years after a deadly plague killed all the Grown-ups, the world's population has nearly vanished. But a group of children have survived and forged a new family, a new life, and together traveled up the coast of Florida, looking for answers.

To their shock, they've found a group of adults, the only Grown-ups they've seen for years, living in an abandoned shopping mall. It's a world the travelers had almost forgotten -- cupcakes, clean clothes, adults to depend on.

But something is terribly wrong. The family must find the truth before it's too late.