In 1889, the small steel town of Johnstown Pennsylvania was nearly wiped off the map by a flood. This was only partly a natural disaster--the breaking of the South Forks dam was not entirely due to an unprecedented rainstorm--the selfish behavior of rich industrialists was also to blame.
High in the hills of Pennsylvania, the rich elite of Pittsburgh--people like the Fricks and the Carnegies, for example--purchased a piece of land to create a summer club. They built a hotel and cabins. They also liked the built-in lake, but decided the old earthen dam could use some improvements...they made it lower and flatter (so they could take carriage rides across) and put in some mesh "fish-gates" so the expensive fish they stocked couldn't escape. These "improvements" would weaken the dam, so when the record-setting rainstorm came along, there was almost no chance the dam would stay intact.
In the middle of the day on May 31, 1889, the South Forks dam collapsed and sent the approximately 20 million tons of water which had been Lake Conemaugh cascading down the valley, wiping out numerous small towns before turning a corner, picking up speed, and hitting Johnstown with a 60 foot tall wall of water, moving at about 40 miles an hour. The town was almost totally destroyed and many lives were lost. The wall of water picked up train cars, houses, trees, and other debris, and through it against a railroad bridge at the bottom of town. This giant pile of detritus stuck against the bridge, and as the waters were still receding caught fire, sending several people trapped in the debris to their deaths.
Of course, none of the wealthy industrialists whose selfish lack of attention created the deadly circumstances were ever held responsible.
David McCullough does an excellent job explaining the historical context of the flood, as well as the events that occurred. He also explains in an easily understandable manner the engineering failures that led to this disaster.
The book is both entertaining and informative, and I'd recommend it to anyone who is interested in turn-of-the century Pennsylvania history.