What would happen if a hole was drilled straight through the Earth from one side to the other and someone jumped in?

If, hypothetically, a massive hole was drilled from one side of the earth, through the center, and back out the other side, without the world collapsing or imploding and someone jumped in what would happen to them. This question is based around the gravity shift that would, assumably, occur halfway down; and is not to be taken literally. If you dropped a person or object down this hole; what would happen when they hit the middle? Would they go past this point, only to be slingshotted back and forth until a neutral point was found? Would the person feel a slow increase in pressure as they fell to eventually be crushed, or would the force of the fall, and the lack of density, be enough to void this pressure? Would they hit the middle like a tomato to a brick wall and splatter as if hitting a solid object? Or some other alternative?...

For this question to be answered properly a certain mindset must be assumed; the person/object DOES not hit the edges of the hole on the way down. They are not killed/destroyed on the way down by anything other than gravity (no, not even a heart attack or Chuck Norris). There is no lack of oxygen. The force of the fall alone does not kill/destroy them/it. The hole cannot be moved or broken or collapsed. The temperatures at the Earths core does not kill/damage them/it. All of these facts are assumed – even if they are not realistic. There are very few exceptions to these rules; i.e, the person can hit the sides of the hole if a logical reason other than trajectory of fall etcetera, is given; If they hit the sides due to the rotation of the Earth or this is a vital part of your theorie, then it is also up for discussion.

This question is purely philosophical, and relative; have fun with it, think outside the box. I’ve pondered this many a time, and I’ve always wondered what others thought…