Americans ; why importance of katrina Hurricane is different , relative to Other hurricanes ?
A couple reasons that add up.
The initial landfall of Katrina was in southern Florida, and while it was a hurricane at that point, it was comparatively minor and did little damage. It wasn't until it got into the Gulf of Mexico that it exploded into a Category 5 (top-tier, in terms of wind) storm, and because of the timing, New Orleans had comparatively short warning - between two and three days.
New Orleans itself is largely below sea level, and protected by a series of levees and pumps. Katrina dumped an impressive amount of rain into this basin on top of a huge tidal surge, overwhelming the ability of the system to drain the water off and causing widespread flooding (which is a larger issue with most hurricanes than wind speed). Coupled with the incomplete evacuation, there were a huge number of people who were caught in the city with no means of escape.
Also as a result of the short warning, the government response was entirely inadequate, and many people who survived the initial storm were left without access clean water for up to a week or more. Recovery of bodies was still taking place two months later in some isolated instances. The director of FEMA at the time ended up resigning over the widely criticized failure of the agency to do its job in the aftermath of the storm.
Finally, New Orleans is a decent sized city with (comparatively, for the US) a lot of history and a rich culture. An event of this scale 'touches' more people than a catastrophe of similar scale happening in, say, Minneapolis.
