Ashes (Ashes Trilogy, 1)

An electromagnetic pulse flashes across the sky, destroying every electronic device, wiping out every computerized system, and killing billions. Alex hiked into the woods to say good-bye to her dead parents and her personal demons. Now desperate to find out what happened after the pulse crushed her to the ground, Alex meets up with Tom ― a young soldier ― and Ellie, a girl whose grandfather was killed by the EMP. For this improvised family and the others who are spared, it’s now a question of who can be trusted and who is no longer human.