The day the lights went out is remembered as Day Zero .
It wasn't just the lights, it was the phones, the computers and just about everything else that made modern society what it was.
Power Loss tells the story of eight individuals, by eight different authors, each trying to come to terms with the blackout and survive in a world that has changed forever.
Various is the correct author for any book with multiple unknown authors, and is acceptable for books with multiple known authors, especially if not all are known or the list is very long (over 50).
If an editor is known, however, Various is not necessary. List the name of the editor as the primary author (with role "editor"). Contributing authors' names follow it.
Note: WorldCat is an excellent resource for finding author information and contents of anthologies.