The warnings came, again and again.
For nearly a decade, scientists told city and state officials that New York faces certain peril - rising sea levels, more frequent flooding and extreme weather patterns. The alarm bells grew louder after Tropical Storm Irene last year, when the city shut down its subway system and water rushed into the Rockaways on Long Island and in Lower Manhattan.
On Tuesday, as New Yorkers woke up to submerged neighbourhoods and water-soaked electrical equipment amid superstorm Sandy, officials took their first tentative steps towards considering major infrastructure changes that could protect the city's fragile shores and eight million residents from repeated disastrous damage.
Governor Andrew Cuomo said the state should consider a levee system or storm surge barriers and face up to the inadequacy of the existing protections.
"The construction of this city did not anticipate these kinds of situations. We are only a few feet above sea level," Cuomo said. "As soon as you breach the sides of Manhattan, you now have a whole infrastructure under the city that fills - the subway system, the foundations for buildings" and the World Trade Centre site.
The Cuomo administration plans talks with city and federal officials about how to proceed. The task could be daunting, given fiscal realities: storm surge barriers, the huge sea gates that some scientists say would be the best protection against floods, could cost as much as US$10 billion.
But many experts say, given what happened with the latest storm, that inertia could be more expensive.
After rising roughly 2.5cm per decade in the last century, coastal waters in New York are expected to climb as fast as 15cm per decade, or 60cm by mid-century, according to a city-appointed scientific panel. That much more water means the city's flood-risk zones could expand in size.
"Look, the city is extremely vulnerable to damaging storm surges just for its geography, and climate change is increasing that risk," said Ben Strauss, director of the sea-level-rise programme at the research group Climate Central in Princeton, New Jersey. "Three of the top-10 highest floods at the Battery [southern tip of Manhattan] since 1900 happened in the last 2-1/2 years. If that's not a wake-up call to take this seriously, I don't know what is."
With an almost eerie foreshadowing, the dangers laid out by scientists as they tried to press public officials for change in recent years describes what happened this week. Subway tunnels filled with water, just as they warned. Tens of thousands of people in Manhattan lost power. The city shut down.
What scientists, who have devoted years of research to the subject, fear most is that, as soon as the storm clean-up is over, the public will move on.
Mayor Michael Bloomberg is known worldwide for his broad environmental vision. But one former official said it had been difficult to move from theoretical planning to concrete actions, and it was hoped that the storm this week would change that.
"A fair question to ask is: have we been as focused as we need to be for emergency preparations," said the former official. "We've just been lucky. We need hardening for the risk we've always faced. Until things happen, people aren't willing to pay for it."
A state report on rising sea levels, issued on the last day of governor David Paterson's administration in 2010, suggested that erecting barriers to restrain floodwaters could be part of a broader approach, along with relocating buildings and people further from the coast.
On Tuesday, Bloomberg said that he was consumed with the task of getting the city going again and that it was too soon to determine what steps should be taken.