1. Columbus prediction, 1658
Christopher Columbus believed the world began in 5343 BC and would last 7000 years. So it would have ended in 1658.
2. Halley's Comet, 1910
Astronomer Camille Flammarion predicted the comet "would impregnate that atmosphere and possibly snuff out all life on the planet."
3. Cuban Missile Crisis, 1962
The Soviets had nuclear weapons, and were threatening to use them.
4. Y2K Problem, January 1, 2000
A Y2K bug was expected to crash enough computers on midnight of 1999 to cause society ceasing to function.
5. The Devil's Number, 1666
The number 666 was in the date, 100,000 Londoners died due to bubonic plague, and the Great Fire of London happened. Some Christians saw the end of times.