Don Boudreaux links to this video explaining the fallacy of the "broken window," first elucidated by Bastiat. The gist of the story is that there is a silver lining to natural and man-made disasters in that as a result of the disaster there is an increase in economic activity. Following the destruction of the Twin Towers for example, people were put to work cleaning up the site, designing and building a visitor's center, etc., requiring all sorts of materials and other productive assets to be employed as a direct consequence of this disaster.
There is, however, a simple test of peoples' perceptions of the great benefits accruing from the destruction caused by natural and man-made disasters. In August of 2005, Hurricane Katrina ripped through (and up) New Orleans and other parts of the Gulf Coast, killing nearly 1,500 people and causing an estimated $125 billion in property damage.
A mere three weeks later, another category 5 hurricane was traversing the Gulf, barreling down on the coast of Texas. Hurricane Rita was predicted to make landfall just north of Galveston, Texas. How many people living in the projected path of Hurricane Rita were elated by the news of this imminent threat, pumping their fists in the air and yelling, "Hot damn, economic growth is headed our way!"? My guess is none.