Con Ed: B'klyn, Manhattan customers should have power in 4 days

"Make no mistake about it: This was a devastating storm, maybe the worst we have ever experienced," Mayor Michael Bloomberg said.

Sandy's nationwide death toll climbed to at least 35, according to the Associated Press.

"Sadly the storm claimed lives throughout the region, including at least 10 in our city ... and we expect that number to go up," Bloomberg said.

In the storm's wake, President Barack Obama issued federal emergency decrees for New York and New Jersey, declaring that "major disasters" existed in both states.

One disaster-forecasting company predicted economic losses could ultimately reach $20 billion, only half insured.

Sandy brought a record storm surge of almost 14 feet to downtown Manhattan, well above the previous record of 10 feet during Hurricane Donna in 1960, the National Weather Service said. Hurricane-force winds as high as 90 miles per hour were recorded, according to Jeffrey Tongue, a meteorologist for the weather service in Brookhaven.

"Hopefully it's a once-in-a-lifetime storm," he told Reuters.