Though there are only two actual deaths in Fences, mortality is a constant theme. Troy Maxson kicks it off by telling a story where he literally wrestled with Death and won. We get several monologues throughout the play where he taunts Death, almost daring Him to try and take him again. In the end, Death does take Troy, but we're left with the impression that Troy doesn't go down without a fight. Fences seems to view human mortality as both a dark inevitability and our ultimate chance for peace. When the gates of heaven open for Troy at the end of the play, we're left with the impression that he's found rest in the afterlife.
Troy's death allows his family, especially Cory, to heal.
Troy triumphs over Death because he never lets fear of it control his life.