"I hope, I pray, that there won't be any loss of life because of it," he said.
While the hurricane's winds registered as only a Category 1 on a scale of five, it packed "astoundingly low" barometric pressure, giving it terrific energy to push water inland, said Kerry Emanuel, a professor of meteorology at MIT.
"We are looking at the highest storm surges ever recorded" in the Northeast, said Jeff Masters, meteorology director for Weather Underground, a private forecasting service. "The energy of the storm surge is off the charts, basically."
In New York City, authorities worried that salt water would seep through the boarded-up street grates and through the sandbags placed at subway entrances, damaging the electrical connections needed to operate the subway.
Hours before landfall, there was graphic evidence of the storm's power.
A construction crane atop a luxury high-rise in New York City collapsed in the wind and dangled precariously 74 floors above the street. Forecasters said the wind at the top the building may have been close to 95 mph.
Off North Carolina, a replica of the 18th-century sailing ship HMS Bounty that was built for the 1962 Marlon Brando movie "Mutiny on the Bounty" went down in the storm, and 14 crew members were rescued by helicopter from rubber lifeboats bobbing in 18-foot seas. Another crew member was found hours later but was unresponsive. The captain was missing.
At Cape May, water sloshed over the seawall, and it punched through dunes in other seaside communities. Sandy also tore away an old section of Atlantic City's historic boardwalk.
"When I think about how much water is already in the streets, and how much more is going to come with high tide tonight, this is going to be devastating," said Bob McDevitt, president of the main Atlantic City casino workers union. "I think this is going to be a really bad situation tonight."