I heard of a play once, can't remember the title. Might you know it...?

When I was studying performace at Uni some years ago, my tutor spoke about a play which he thought was the truly saddest play ever written. I really want to read it, but cannot remember the playwright nor the play title. What I do remember, though, is that it was within the last 200 years and was the last play that the playwright wrote before he died. It was a personal and semi-autobiographical play about the destruction of his family. Because it was so personal, he did not ever want it to be published at all. However, only 1 year after his death, his wife now widowed decided to go against his wish and publish it. Does this little bit of theatre trivia spark something in you? Does anyone out there know what play this could be? Thanks!