Also note in the article the estimated time to rescue:
"Regional and national rescue resources would have to respond as rapidly as possible and would require augmentation by local private vessels (assuming some survived). And, even with this help, federal and state governments have estimated that it would take 10 days to rescue all those stranded within the city. No shelters within the city would be free of risk from rising water."
Knowing this, the local and state officials should have asked for more help and done more to reduce the number who actually stayed in the city. The rescue effort so far has been amazing, but the city moved resources from law and order to the rescue effort, instead of leaving the police in place and utilizing the National Guard to aid in the search.