The first book of 'Tales of the Triad'.
Seven billion people die overnight, killed by a change affecting entire galaxies. John, a resident of Florida, awakens to find himself on a plateau half a mile high in central Florida, the only survivor in the entire state. Others awaken and find themselves alone in destroyed cities or laying beside empty highways, changed by the event in ways they cannot yet understand.
Christine, a thirtyish middle school teacher finds herself with the body of a sixteen year old. A really nice body.
Carl discovers his sixty year old body is able to leap cars, he no longer needs his trifocals and he really likes the new ax he found.
Joshua was not happy to see his bike wrapped around the tree, but he was the only person in his group who could fire a gun. He could outrun a deer too, something that came in handy when the group got hungry.
Dogg still drinks too much and eats junk food, when he can find it, but the pack of wolves listens to his every command.
Ben can't do anything special, and he is pretty much the same as before. But being big, strong and kind is a good thing. At least the half a dozen orphaned children he collects from the ruins think it is. Frightened of a stranger at first, Ben soon wins them over and protects them as best he can.
He and the few survivors across the world must struggle to deal with a universe where magic has replaced science and all of mans inventions no longer exist.