Right .. here's my thinking.
Mass causes mavity.
So .. if theoretically there was a room right in the middle of the earth, you would NOT get crushed by the pressure. As the mass is all around you in approximate equal measure.
So for all those 'pressure would crush you' guys -- I disagree. I think you would be ripped apart onto the walls of the room, rather then crushed into a red bloody ball in the centre of it..
lol wut...