How does one explain death to a 3 year old?

A few weeks ago we were at my moms house and Brooke realized that the fish that lived in the bathroom was gone. It actually has been gone since last September or October. So she asked me where the fish was and I told her it died and went to Heaven to live with Heavenly Father and Jesus.

In conversations to follow we have talked about how we lived in Heaven before and that is where the baby brother is coming from and that when we die we will return.

Well this morning I caught the tale end of a conversation between Addie and Brooke. Addie said "do you want to go to Heaven" Brooke said "no." Then Addie said "well then, don't die."