What are the rules in baseball concerning a distroyed ball?

This is not covered in the rules, so the umpire gets to decide what to do per rule 9.01(c). Apparently what happened is that the players played on as best they could, then when play relaxed, time was called and the ball was removed from play.

This is a situation where the umpire could decide to do whatever he felt necessary to nullify the problem, but the best tack is to let the play lie, otherwise, you can get into a morass of "woulda, coulda, shoulda."

If you're asking about the situation from a few days ago, it was play on, then remove the ball. If you're asking about the situation in the book/movie, "The Natural" where Roy Hobbs splits a ball in half, a baseball isn't made in a way where that would occur.

When the home plate umpire is made aware of this, a new ball will be put in play.

neither becomes a foul ball and play with new one.

The ball can still be in play if the innards are still inside the over. But after the play is made the ball must be removed from play and replaced with a new one. This happened in April with a ball hit by Martin Maldonado.