There's been a couple times when I've lost some or most of a chapter's worth of work because one way or another, the edit window was closed before I hit the save button. Once or twice it's been my fault, like closing the browser without meaning to, but sometimes it's for reasons that I couldn't control—one time my computer crashed, and most recently because my apartment lost power after a storm. I think it would be nice if chapters could occasionally auto-save while you're editing them, kind of like how editing a Google doc works.
