Sadly, we are accustomed to the regular occurrence of natural disasters. It seems as if every few months a storm, flood, tsunami or earthquake devastates a country, exacts a frightening toll, and reminds us that we remain susceptible to the forces of the physical world. In the perennial struggle between humankind and nature, civilization's victories are temporary at best.

Most of us believe that such disasters are not "our" problems. Readers of this newspaper live with the ever-present risk of a massive earthquake, but that reality does not penetrate daily life. Yet the risk of being visited by a calamity is real, as the citizens of the U.S. Gulf Coast discovered last week.

Hurricane Katrina, a "Category 4" storm (5 being the most destructive) with winds in excess of 200 kph hit the Gulf Coast of the United States on Aug. 29. The storm made landfall at New Orleans, a city built behind levees; it is estimated that 80 percent of the city is under sea level, rendering it vulnerable to flooding if those levees do not hold. Many city residents had left the city, but the poorest among them, without access to transportation, were forced to remain. The levees broke, New Orleans flooded, and scenes of despair and degradation, chaos and confusion were shown to all the world.