“Mere seconds before the Earth is to be demolished by an alien construction crew, journeyman Arthur Dent is swept off the planet by his friend Ford Prefect.”
The Douglas Adams book was made into a movie in 2005 and the opening scene describes how dolphins tried to warn humans of the apocalypse, but left when they realized mankind wasn’t receiving their message.
“It's an important and popular fact that things are not always what they seem,” the movie opens with.
“For instance, on the planet Earth, Man had always assumed that he was the most intelligent species occupying the planet, instead of the *third* most intelligent. The second most intelligent creatures were of course dolphins who, curiously enough, had long known of the impending destruction of the planet earth. They had made many attempts to alert mankind to the danger, but most of their communications were misinterpreted as amusing attempts to punch footballs or whistle for tidbits. So they eventually decided they would leave earth by their own means. The last ever dolphin message was misinterpreted as a surprisingly sophisticated attempt to do a double backward somersault through a hoop while whistling 'The Star-Spangled Banner,' but in fact the message was this: So long and thanks for all the fish.”
When the Dana Point story was reported in 2012, people were quick to blame their strange behavior on the end of the world. But since humankind generally seems to be quick to "cry apocalypse"; see the Mayan calendar prediction of Dec. 21, 2012, the pope's resignation, the meteor that hit Russia and various other occurences.
Check out the video of the Dana Point stampede below: