Aftershock

On the last day of school, a huge earthquake hits western Canada. Amy is surprised that it's Mara, her half-sister, who finally comes for her, since they hardly know each other. There's no word from any of their parents, and their homes have been destroyed. Amy and Mara set out on a perilous journey from their suburb into the city to search for their parents. As they walk day and night, the scope of the horrific destruction becomes clear. Have their parents survived the disaster? -- adapted from back cover and perusal of book