What happens in the book The Westing Game that leads Sam Westing to Die?

In the beginning of the book, they say that Sam Westing's corpse was found. But it was actually a wax dummy molded into Sam Westing's body 15 years ago (in the book). Sam Westing is Sandy mc southers, Julian eastman & barney northrup. sandy mcsouthers fakes his death. turtle wins but never tells anyone.