Around 1520 the London astrologers calculated the world would end by flooded which would start in London on Feb. 1, 1524. 20,000 Londoners' left their homes and went to higher ground. Nothing happened ... didn't even rain that day in London.
The scientist of the day found an error in their calculations and the date was revised ... but alas nothing happened.
The soothsayer of today continue this tradition....