Who died in the book The Westing Game by Ellen Raskin?

Sam Westing and Bertha Crow’s daughter Violet died. 

Even though she never appears in the book, Violet Westing heavily influences events.  Her death devastates her mother and father.  It is the cause of Crow’s alcoholism and mental health issues, and Sam Westing’s bizarre eccentricities.  Neither parent recovers. 

Violet Westing was supposed to be married.  She was young, and had her whole life in front of her. 

The paper king’s later years were marred by tragedy. His only daughter, Violet, drowned on the eve of her wedding, and two years later his troubled wife deserted their home. Although Mr. Westing obtained a divorce, he never remarried. (Ch. 4) 

The mystery of who killed Sam Westing stems from his daughter’s death.  Westing writes a will and concocts an elaborate game to find out which of his heirs is worthy of his fortune, but he is never actually dead.  Westing is there the whole time in his various disguises as Barney Northrup and Sandy McSouthers. 

Sam Westing has his fun, and finds that not all of his heirs are hopeless. 

His watery blue eyes stared at her over his rimless half-glasses. Hard eyes. His teeth were white, not quite even (no one would ever guess they were false). He was smiling. He wasn’t angry with her, he was smiling.

“Hi, Sandy,” Turtle said. “I won!" (Ch. 27) 

Eventually, Sam Westing does die.  He dies of old age, with Turtle by his side.  

So while there are a lot of explosions and questions about who killed Sam Westing, the only real deaths in this novel are of natural causes.  Sam Westing’s daughter drowned, and Sam Westing died of old age.  Before he died, he got to know all of his relatives a lot better.