The Bridge of San Luis Rey

In Lima, Peru, an ancient Incan rope bridge breaks and plunges five people to their deaths. A Franciscan monk witnesses it and decides to investigate the lives of the five people, in order to prove that God is just, that He had a purpose in choosing those five to die, on that day, on that bridge.
And so we learn of the lives of the Marquesa de Santamayor and young Pepita her companion; of Esteban, a young man of the city; and of Uncle Pio and Don Jaime, the mentor and son, respectively, of a famous actress in Lima. We see how many of their lives intersect, we learn of their dreams, their struggles, and the events that led to them being on the bridge that day.
The Bridge of San Luis Rey earned Thornton Wilder the first of his three Pulitzers. The novel's structure, in which a major event is presented followed by the backstory of the people involved, has been duplicated countless times in books, plays, and movies. It was the best-selling book the year of its release, and has never been out of print since.