There was a large beautiful lake once. It was formed by a relatively common type of hydro-electric generating dam that blocked a strong river in a long peaceful valley in a richly green, verdant countryside. Just over forty-five miles further down the valley, a small community of about 12,000 people lived happily.

One day, an almost imperceptible earth tremor caused a weak zone in the dam’s concrete structure to release, cracking a line that crazed outwards from the center of the dam. Under the pressure of nearly a billion tons of water behind the dam, the fracture rapidly expanded, first horizontally for several hundred feet, then forking into numerous other cracks that went upward and downward from the source rupture.

Within minutes, large sections of concrete, lubricated by the water pressuring through the cracks between them, began sliding outwards. Massive blocks of concrete slipped out of place, thundering down to the base of the dam as a 12-storey-high mass of water exploded out over them. Nearby animals, and a small group of people, were terrified at the deafening thunder of hundreds of tons of concrete and water crashing into the valley. The ground shook and emitted ear-numbing roars of low-frequency tectonic rumbles, while the cracking and crashing sounds of hundreds of breaking trees echoed outwards through the air.

The people many miles down the valley from the unexpectedly shattered dam that afternoon thought they were having a very fine day; it was warm, sunny and pleasant.
Even as the now-five-storey-high wall of water exploded down the path of the valley, destroying everything in its way, the people much farther along went about their business as usual.

A few who did have a radio turned on heard a news flash that the dam up the valley had broken. Of those few, about three quarters of them felt that the government would take care of it; after all, it was only a broken dam, miles and miles away. The remaining quarter, who had the wherewithal to accurately visualize the long-range consequences of a broken dam releasing many millions of tons of water at once down a valley, immediately made plans to get out of the way of the oncoming disaster.

As they frantically threw a few necessities into the backs of their cars and gathered up their families and pets, many of their neighbours watching in amusement pooh-poohed their actions. Some of the comments overheard were:
   “It’s only water.”
   “The government will look after things.”
   “Nonsense. I never heard of it, so it didn’t happen.”
   “Don’t be so hyper… take your time…. We’ve got lots of time.”
   “It’s never been that bad before; it can’t possibly be that bad now.”
   “Hey, I know all about these things… no worries, mate.”
   “It’s just a conspiracy theory. Don’t get worked up about it.”
   “You know the news… they’re always getting these things wrong.”
   “It’s just a scare tactic. We’re fine.”