Just one of many reports--you can easily find others--detailing the post-Sandy housing crisis. Given what we know about the resources and technological capabilities possessed by the United States, it's not hard to see how we could react with disbelief that the U.S. could prove itself so vulnerable to Mother Nature.
But imagine if the government woke up (it has to be the government, or some organization with the power to override the human drive to procreate) and decided to make population shrinkage a priority, with the goal of achieving the following condition.
Large areas would be left depopulated, yet their infrastructure maintaining, primarily through the use of technology, including robots, to ensure that they remain livable. Transportation infrastructure is built up to ensure that the population of entire cities can be quickly transported away from an incoming storm and into these safe zones.
Imagine the lives that could be saved, and the suffering that could be averted, if the government had the will to implement such a scheme.
Of course this would be an enormous undertaking, fraught with obstacles--there is no need to dwell on that. But the U.S. has accomplished great things before, and could do so again if we had the political will.