Even the most original movie plot is inspired by something, usually a book, comic book franchise, or another movie. Biopics are based on real people. Horror films, as we've seen, often follow old and timeworn plots and details that are used over and over. But some are inspired by mysterious but real news items. Yes, they are changed a lot to give some kind of explanation and backstory, but the basic premise is ripped from the headlines -and the legends that sometimes grow up around those headlines. You might be surprised that even the 1958 movie The Blob was inspired by a news item.
Premise: A mysterious alien life-form terrorizes a small town and consumes everything in its path as it grows bigger and bigger.
Real-Life Inspiration: Believe it or not, The Blob is based on a New York Times article from 1950 titled, "A ‘Saucer’ Floats to Earth And a Theory Is Dished Up." The story followed four Philadelphia police officers who came into contact with a strange gooey material, which is now believed to be "Star Jelly," a transparent gelatinous substance. When one of the officers tried to move the goo, it started to dissolve and evaporate, so there was nothing to show the FBI when they arrived on the scene except a spot on the ground.
Read about eight more such news stories that inspired horror films at Mental Floss.