She wasn't breathing. She was also under the water, and she looked unconscious.
He pushed through the door, took her by the arm, and pulled her out of the water. If she didn't struggle, he was going to pull her over the edge of the bath and use CPR, because has far as he could tell she was drowning. He didn't understand. She'd seemed fine - at least in her thoughts - before disappearing completely. Had she just turned out like a light? Had she been overtaken by exhaustion? He didn't know, but regardless, he wasn't going to let her drown.