Thornton Wilder was asked how he got the ideas for his books, and he said — or his plays — and he said, “I imagine a story that I would like to read, or see done on the stage. And if nobody has written that book or that play, I write it so that I can read it or I can see it on the stage.” Well, I wanted to be able to read a really first-rate book about the incredible story behind the disaster at Johnstown in 1889, and I found there was no such book. But having read that interview I thought, “Well, maybe you could write the book that you would like to read.” And I am convinced that the only way we ever really learn anything is by doing it.