In 1499, Johannes Söffler predicted that a great flood would nearly wipe out Earth's population. Given that we live in a very crowded 2019, you can probably guess how that worked out. But Söffler's doomsday prediction did come true for at least one unlucky individual. 

Sources:

Söffler, Johannes. Wikipedia. Last accessed on November 11, 2019. https://en.wikipedia.org/wiki/Johannes_St%C3%B6ffler

Strauss, Mark. Ten Notable Apocalypses That (Obviously) Didn't Happen. Smithsonian. November 12, 2009. https://www.smithsonianmag.com/history/ten-notable-apocalypses-that-obviously-didnt-happen-9126331/

Dr. Vitelli, Romeo. Storming the Ark. The James Randi Educational Foundation. January 25, 2011. http://archive.randi.org/site/index.php/swift-blog/1198-storming-the-ark.html