To delete a Community, navigate to Manage Communities in Teacher Tools and click the pencil and paper icon to the right of the Community name and access code to edit it. You can delete the selected Community by clicking the delete button at the bottom of the page. Be aware that if something has been shared outside of the Community (to the Main Stream), the shared version of that post will still remain because items are duplicated when you share them.
WARNING: Deleting a Community removes all announcements, posts, and comments associated with that Community. This action cannot be undone and Communities are not recoverable once deleted.