What happened to the characters in the westing game?

Sam Westing doesn't tell this story, but Sandy McSouthers did; but Sam Westing and Sandy ends up to be the same person.

Once upon a time, two young boys made a bet that the other could stay in the Westing house longer than the other. So the boys went in, and within about a minute, one of the boys came running out screaming with blood on his hands, and then jumped off a cliff nearby. Seconds later, the other boy came out screaming "purple waves" and was then taken to an insane asylum.