Last Survivors: #2 Dead and The Gone by Susan Pfeffer
Life as we knew it is over...only the unlucky survive. At the moment the asteroid hits the moon, Alex Morales' young life changes. Forever. As freak weather engulfs the globe, New York is plunged into a nightmare from which many will never wake. With no food, no electricity, and no parents, Alex must keep himself and his sisters alive...whatever the cost.