The Oyster Creek nuclear power plant in Ocean County just north of the resort of Atlantic City, was already on a scheduled outage as the massive storm made landfall nearby on the Atlantic Coast.
The Nuclear Regulatory Commission said the plant sounded an alert – one notch above the lowest of the watchdog's four categories for action levels – as the facility recorded a designated high mark for water inside.
"Water level is rising in the intake structure due to a combination of a rising tide, wind direction and storm surge," the commission said in a statement.
"It is anticipated water levels will begin to abate within the next several hours," it said.
The regulator said all plants in the storm's way were in safe condition and that inspectors were working to verify independently that operators underwent proper procedures.
Concerns about nuclear power spiked in March 2011 in Japan's massive earthquake and tsunami caused a meltdown at the Fukushima plant, triggering clouds of radiation and forcing tens of thousands of people to flee their homes – perhaps permanently.
Sandy has ravaged the eastern US, plunging hundreds of thousands into darkness and flooding the subway and the usually bustling streets underneath New York's iconic skyline.
Counting the cost
As the US braced for Hurricane Sandy, the Caribbean nations that have already faced its fury were burying the dead, finding shelter for the homeless and counting the economic cost of the fiercest winds and rain that many have seen in a decade.
At least 69 people have died in six countries since the end of last week as Sandy ripped its way northwards with gusts in excess of 177km/h and downpours that engulfed homes, crops and roads.
Hardest hit is Haiti. Although not directly in the path of the hurricane, the poorest nation in the Americas has confirmed 52 dead and at least a dozen more missing as flimsy buildings were engulfed in mudslides or swept out to sea by flood tides.
A worse humanitarian disaster could follow. According to the government in Port-au-Prince, about 200 000 people are homeless, though emergency shelter has only been provided for 17 000.
In addition to the short-term fears of cholera and other water-borne disease, the prime minister, Laurent Lamothe warned of food shortages because crops have been badly damaged.
"The economy took a huge hit," Lamothe told Reuters as he revealed plans to appeal to the international community for emergency aid.
Sea water floods the Ground Zero construction site Oct. 29, 2012, in New York as Sandy continued on its path forcing the shutdown of mass transit, schools and financial markets, sending coastal residents fleeing, and threatening a dangerous mix of high winds and soaking rain. (Photo: abcnews.go.com)
Picking up the pieces
Cuba is also picking up the pieces after extensive loss of life and economic impacts. The Communist party newspaper Granma reported 11 dead and damage to 137 000 homes. It said recovery would take years.
The greatest devastation appears to be in Santiago, where schools, hospitals, homes and churches were damaged. In the city, the stained glass windows of the cathedral were shattered, the zinc roofs of shanty town communities were seen floating away and many areas were still without power and running water on Monday. In the fields, between a fifth and a third of Cuba's coffee crop has been decimated at a time that ought to be the peak of the harvest season.
"We can say that we have had a great hurricane in the east and a small 'Flora' [the name of a destructive 1964 hurricane] in the centre of the country," President Raul Castro said on a visit to the affected provinces, according to the state-run National Information Agency.
Smaller scale fatalities and damage were also reported in Jamaica, the Dominican Republic, Puerto Rico and the Bahamas, where sea waters surged over coastal barriers to deluge roads and buildings.
Venezuela has been among the first to respond to the calls for assistance, providing food, drinking water and equipment to Haiti and Cuba.
Disrupting campaigns
The onslaught of Hurricane Sandy forced US President Barack Obama and Republican hopeful Mitt Romney to suspend campaigning for at least 48 hours – time both teams desperately needed in the crucial final stretch to Election Day next week.
The two presidential candidates cancelled all scheduled events until at least midnight on Tuesday but there could be further disruption for much of the rest of the week, with flooding and power blackouts also taking their toll on the campaign teams' movements.
Early voting has already been suspended in some states – where the Obama campaign had hoped to make crucial gains before the election on November 6.
Each team headquarters sent out instructions to switch from campaigning if need be to help the rescue services and told volunteers in affected areas to stay at home. The advice even included small practical points, such as the Romney team advising supporters to remove any election placards that could become flying projectiles in the storm.
The impact on the respective campaigns is unpredictable.
David Axelrod, Obama's campaign manager, told reporters: "In terms of the logistics, we are obviously going to lose a bunch of campaign time; this is as it has to be and we will try to make it up on the back end.
Obama abandoned planned rallies in Florida on Monday morning and in Ohio in the afternoon in order to return to Washington after being told the storm was shaping up to be worse than expected and that if he delayed, they might have trouble getting back to the capital.
A row of houses stands in floodwaters at Grassy Sound in North Wildwood, N.J., as Hurricane Sandy pounds the East Coast on Oct. 29, 2012 as the powerful storm made the westward lurch and took dead aim at New Jersey and Delaware, washing away part of the Atlantic City boardwalk, and threatening to cripple Wall Street and the New York subway system with an epic surge of seawater. (Photo: abcnews.go.com)
Impact on voting
A plane full of journalists accompanying him on the campaign trail had to be left behind in Florida.
Asked later about the impact of the storm on the election campaign, the president presented himself as being above such things as consideration of how it would affect voting. "I am not worried at this point about the impact on the election. I'm worried about the impact on families and I'm worried about the impact on our first responders. I'm worried about the impact on our economy and on transportation," Obama said.
"The election will take care of itself next week. Right now, our number one priority is to make sure that we are saving lives, that our search-and-rescue teams are going to be in place, that people are going to get the food, the water, the shelter that they need in case of emergency, and that we respond as quickly as possible to get the economy back on track."
Obama had to return to the White House to be seen to be on the spot, monitoring the storm and in regular contact with the emergency services. To have continued campaigning while millions of people faced the prospect of costly damage might have alienated voters.
Romney's campaign team reached the same conclusion. Having rescheduled campaigning to take him away from states on the storm path, such as Virginia, to Ohio, he too changed his mind and followed Obama in cancelling all events.
Romney realised it might appear callous to be seen standing in front of rallies in sunshine, while people on the east coast faced disruption and damage. His vice-presidential running mate, Paul Ryan, also scrapped campaign events.
Gail Gitcho, a Romney communications director, said: "Out of sensitivity for the millions of Americans in the path of Hurricane Sandy, we are cancelling tonight's events with Governor Romney in Wisconsin and Congressman Ryan in Melbourne and Lakeland, Florida. We are also cancelling all events currently scheduled for both Governor Romney and Congressman Ryan on Tuesday.
"Governor Romney believes this is a time for the nation and its leaders to come together to focus on those Americans who are in harm's way."
'Big and powerful'
Obama described the storm as "big and powerful" but took solace in the fact that the emergency services have had a few days to prepare.
Echoing the Romney campaign about America coming together in time of crisis, he said: "It's going to be a difficult storm. The great thing about America is when we go through tough times like this we all pull together. We look out for our friends. We look out for our neighbours. And we set aside whatever issues we may have otherwise to make sure that we respond appropriately and with swiftness. And that's exactly what I anticipate is going to happen here."
Obama said he had spoken to all the governors of the states in the path of the storm to make sure food and water and emergency generation would be available for the hardest-hit.
"The most important message that I have for the public right now is, please listen to what your state and local officials are saying. When they tell you to evacuate, you need to evacuate. Do not delay. Don't pause; don't question the instructions that are being given, because this is a serious storm and it could potentially have fatal consequences if people haven't acted quickly," he said.
He told the public to expect blackouts and warned that it might take time to get the power back on and transport restored.
Neither side has as yet attempted to make political capital out of the storm. Romney is potentially exposed after saying in a debate during the Republican primaries and caucuses that he favoured cutting the Federal Emergency Management Agency (Fema) to help reduce the deficit.
An historic ferryboat named the Binghamton is swamped by the waves on the Hudson River in Edgewater, N.J., Oct. 29, 2012, as Hurricane Sandy lashed the East Coast. (Photo: abcnews.go.com)
Emergency spending
The Romney campaign stood by that assessment, saying it was not proposing to abolish Fema, only that decisions about emergency spending should rest primarily with states rather than with the federal government.
Ryan Williams, a Romney spokesperson, said in a statement: "Governor Romney believes that states should be in charge of emergency management in responding to storms and other natural disasters in their jurisdictions.
"As the first responders, states are in the best position to aid affected individuals and communities, and to direct resources and assistance to where they are needed most. This includes help from the federal government and Fema."
With polls showing the two campaigns tied neck and neck, both Obama and Romney were initially reluctant to quit the campaign trail.
Obama, after rearranging his schedule, tried to squeeze in two events before the storm hit, flying to Florida on Sunday evening to be in position for a joint rally with former president Bill Clinton in Orlando on Monday morning. He stayed overnight in Florida, but his team advised him against going ahead with the rally, leaving Clinton to do it on his own. – © Guardian News and Media 2012, Sapa, AFP
