Whatever it was had to be able to get under the deck. Mind you, this deck is near ground level. The kittens and their mother had to squeeze under the bottom of the joists to move from bay to bay. The opening to get under the deck is a missing deck board.If the tom killed them, you should eventually find the bodies. I'm sort of thinking like Shad (scary, yeah) that it was something else - perhaps coyote or even a fox.