My filesystem ate a folder

That’s how it looks like. I’m absolutely sure where I saved it and with what name. However the folder with couple of other files is gone overnight and find/ | grep “industrial” returns nothing. Nevertheless Writer saved it successfully giving no error message. I can’t really imagine what happened to it. But since computer-related posts often are in the top at tr.ee, perhaps someone smarter knows the answer. For now I have to get used to the idea of writing my essay once again which is annoying.