Alone - Tome 1, The Vanishing

Ivan, Leila, Camille, Terry, Dodzi. Five children who have never met each other, who live very different lives in a small city. Then, one day, they all wake up in their empty homes, walk out into empty streets and wander through the empty city. No adults, no other children; just the five of them eventually finding each other, and forced to band together to face the inevitable questions - and the dangers of a modern city suddenly emptied of its inhabitants.