America's wealth and technical prowess contributes to a false sense of security in the face of natural disasters such as Hurricane Katrina, says Dennis S. Miletti, a top expert on disaster prevention.

"We rely on technology and we end up thinking as human beings that we're totally safe, and we're not," said Miletti, of the University of Colorado. "The bottom line is we have a very unsafe planet." By one critical measure, the impact on populations, statistics show the planet to be increasingly unsafe. More than 2.5 billion people were affected by floods, earthquakes, hurricanes and other natural disasters between 1994 and 2003, a 60 percent increase over the previous two 10-year periods, U.N. officials reported at a conference on disaster prevention in January. Those numbers don't include millions displaced by last December's tsunami, which killed an estimated 180,000 people as its monstrous waves swept over coastlines from Indonesia's Aceh province to Trincomalee, Sri Lanka, and beyond.

Too often, says Miletti, Americans leave themselves vulnerable.

The way America builds too often invites disasters, experts say -- by draining Florida swampland and bulldozing California hillsides, for example, disrupting natural runoff and magnifying flood hazards. "We're building our communities in ways that aren't compatible with the natural perils we have," Miletti said.

Experts say this sort of cultural arrogance extends to our emergency planning, noting that Cuba, Bangladesh, and Jamaica have recently weathered severe storms with only a fraction of the deaths already seen from Katrina.

Like many around the world, Barbara Carby, Jamaica's disaster coordinator, watched in disbelief as catastrophe unfolded on the U.S. Gulf Coast. "We always have resource constraints," she said. "That's not a problem the U.S. has. But because they have the resources, they may not pay enough attention to preparedness and awareness, and to educating the public how to help themselves."