The play Our Town is remarkable in respect to the thematic changes that it undergoes. The play traces the development of life, and shows how people go through birth, youth, love and death in the same way. This does not make the experiences of people less unique. In fact, it makes them more so, as it connects all humans in a similar way.
Wilder ends the play with the topic of death. This serves two purposes. On the one hand, this illustrates how all lives end, and the impact that death has on those who remain. It also suggests that death is the ultimate "end," which is why it becomes the end in the play as well. The second purpose is to remark on the fact that humans rarely appreciate their lives while they have it, and they forget to think of the inevitability and reality of death.