When deleting a fork, the UI prompts all indicate you are deleting the origin repo - not the fork. It should be much clearer that this action only affects the fork and not the origin.
Metadata Update from @pingou: - Issue tagged with: bug, easyfix
Metadata Update from @pingou: - Issue assigned to pingou
Commit ad0a72b8 fixes this issue
Metadata Update from @lslebodn: - Issue tagged with: IDM