Hurricane!

Hurricane in New York City? It's happened before and scientists say it's likely to happen again.

Because of the population density, a successful evacuation of vulnerable low-lying areas in and around New York City and metropolitan New Jersey would actually have to start sooner than what is typically ordered in Florida and elsewhere, officials have determined based on studies by the Army Corps of Engineers.

But hurricanes move more quickly and become very difficult to predict when they head north of the Carolinas. In a likely scenario, experts say, there might only be hours of warning.

History reveals that New York and the Northeast have been hit hard before, and with little warning. Scientists say the next major hurricane to strike the city is a question of when, not if.