When Abby slaughters the bullies, we see most of the scene from Owen's underwater point of view. First, a decapitated head floats down, leaving a trail of blood. Then, more dismembered bodies splash into the water. We get the sense that the pool water around Owen should be pretty bloody. Yet, when he surfaces, the water around him is completely clear, with no evidence of any blood or bodies.
The name of the town where the story takes place, "Los Alamos", means "the cotton woods." so it's only appropriate that the story takes place in the winter, when all of the woods are covered with white snow.