I read recently about supermassive black holes and how they might even have a density close to that of water!! Far out. It got me thinking about the structures of black holes. Would someone be able to survive, "swimming" in the center of such a body. Of course they'd be crushed but it got me thinking. What if a black hole, was hollow? Let's say the material outside of the central hollow of the, say spherical, black hole was large enough to create an event horizon. What happens to those within the 'hollow' of the black hole. Let's say they got their before enough material accummulated to form an event horizon, and lived there dyson sphere style! I'm just adding narrative here! :E Since the gravity within such a hollow, due to the mass around it, is zero, would bodies inside the hollow feel any gravity due to the black hole, and would they expierience any dilation as a result? As a further query to tack on at the end, when hawking radiation has 'melted' the black hole away, will everyone still be alive inside? Or will the event horizon give way to a scene from the movie Event Horizon!! Have a nice halloween!