You may be able to recover some of the files. Try this.

http://blog.room34.com/archives/25

BTW re: the part where it says "Then navigate to the directory where the zip file is",
Terminal opens to your home directory by default, so if you move the zip file there first you won't have to worry about "Then navigate to the directory where the zip file is", you can run the commands just as they say straight from Terminal.

Or check this out, about half way down the page, how to repair a damaged file. Work on a copy of the file.

http://apple.stackexchange.com/questions...ip-archive-file