While not about earthquakes, preparedness is on-topic...so....New Orleans has a real problem deciding what to do about Hurricane Ivan...even though Ivan has weakened to about 140 mph, a worst-case strike...maybe coming in from SE to NW with eye a few miles south of New orleans, might put too high a storm surge into Lake Ponchartrain for the dikes to hold. And, I may have this wrong, but when I lived in New orleans the dikes were only 16 or 17 feet above sealevel....and you can get a 20 or 25 foot storm surge if Ivan was still 160 mph ...but, at 140 mph it would be cutting it close. New Orleans is between 0 and 14 feet below sealevel....heavy rains have to be pumped out. Do the math...there could be areas with 30+ feet of water...completely over houses. But, it is still more likely than not that Ivan's eye will pass east of New Orleans and the north winds on the west side will not cause a storm surge. It is not all that easy to get out of New Orleans or its suburbs....a bridge across the Mississippi, a long bridge across Lake Ponchartrain, and highway 10 to the east and west. So, when I was there, there was talk of vertical evacuation....bring people into the downtown tall buildings...
So, if you were Mayor/governor, what would you do? New orleans is under a Hurricane watch, and that will probably be changed to a warning at 5 PM eastern....
Chris