Broken Sky: An apocalyptic journey (Sky Saga)

An explosion on the moon sets off a chain of events that no one expected...
Until a few minutes ago, Sky's biggest worry was trying to get access to the internet again after losing her privileges-for hacking into a university's library server. Then, the moon explodes, her dad leaves, and the local gas station goes up in flames. Sky and family flee the city, but when a stop to refuel turns deadly, Sky will have to expose her secret to save her little brother.
Gray tries to put on a brave face as his father packs, after being recalled to duty. Left alone, waiting for his estranged mom to collect him, Gray watches the erupting confusion on LA's streets outside his window. Hours later, when a bullet shatters his living room window and no sign of Mom, Gray sets out for his dad's friend's house, but with the chaos breaking out all around, and men with knives chasing him down alleys, Gray will have to rely on an unlikely hero if he wants to survive.

A prequel to the series The Sky Saga, and can be read as a standalone series.
Recommended for 15+ years old. Mature content: swearing, mild horror & gore, violence, and death.