Is it browser or on the hard drive?
browser, you might try looking in the browser history and go to a different save.
If local on your hard drive, the only way I know to recover is an archive. But with that you have to archive fairly often to keep your progress.
other than that and publishing a story as a back up in case of crashes. I do not know of away to recover. I guess it is similar to short term versus long term memory. Get konked on the head and the short term is first to go.
But I am not a computer programer or anything like that. It is just my experience with using different software.
So moral of the story is publish a story or archive all your stories often. That way you have less to redo in case of a computer crash :)