May, 1947 - Spitzbergen, Sweden:
A report by journalist Dorothy Kilgallen stated that British scientists and airmen were excavating the wreckage of a mysterious flying ship.
The Swedish military is said to have acknowledged its extraterrestrial origin and reported 17 bodies were found. The story appeared as a tiny blip for only one day in the U.S. news media before it was allegedly silenced by the military.
But a respectable number of person remember having read the short article about this case in various newspaper.
... Or so it goes.
Read more about the Dorothy Kilgallen affair here.