At least 13 people were killed in the United States and Canada as the megastorm Sandy slammed into the US east coast today.
New York City and Atlantic City were among the worst-hit areas as Sandy roared ashore, bringing with it a huge storm surge.
Follow our live blog for updates (All times AEDT):
Large parts of lower Manhattan are flooded, with widespread power cuts and electrical fires.
There are fears of widespread flooding along Long Island Sound.
New York's 911 system has been inundated with 10,000 calls every half hour.
The storm's wind field stretched from the Canadian border to South Carolina.
7:10pm: NRL Star Johnathan Thurston is one of the Australians caught up in the storm.
Thurston has been holidaying in New York and told the situation was pretty tense.
"I think everyone's shitting bricks just quietly."
He says the storm has put a "bit of a dampener" on his holiday, but they have been having fun until now.
"At this stage it looks like we will be staying in New York an extra couple of nights than planned, but it could be worse, we could be stuck somewhere else, we are New York City so that's alright."
6:07pm: More than 100 firefighters have been battling a blaze that broke out in Breezy Point, Queens - a small beach community that has been severely affected by flooding.
NBC New York has .
5:39pm: The US Coast Guard has tweeted this photo of the replica ship HMS Bounty, which sank in 18-foot seas.
The Coast Guard rescued 14 crew in a dramatic helicopter rescue, but one woman died and the captain is still missing.
5:18pm: Surging seawater has flooded seven New York subway tunnels and six bus garages.
Metropolitan Transportation Authority chairman Joseph Lhota calls it "the worst disaster for city transport in a century".
"The New York City subway system is 108 years old, but it has never faced a disaster as devastating as what we experienced last night."
4:53pm: This just in from the photo desk:
4:40pm: The US election has been pushed aside by Sandy, but an uncomfortable political question emerges. Which candidate stands to lose or gain ground?
Dr Michael Ondaatje from the United States Studies Centre discusses the political implications of the disaster.
4:24pm: Greg Carbin from the US Storm Prediction Centre created this animation showing Superstorm Sandy's landfall through the measure of surface pressure over 23 hours starting from Sunday evening.
4:13pm: showing the damage caused by Superstorm Sandy.
4:01pm: Check out this of floodwaters surging through the Brooklyn Battery Tunnel in New York City.
3:42pm: This just in from the photo desk:
One of the Con Ed workers pulled from the floodwater, Angelo Amato, told Reuters he was part of a crew who had offered to work through the storm.
"This is what happens when you volunteer."
3:07pm: On Twitter, New Jersey's governor says he might have to cancel Halloween.
"If conditions are not safe on Wednesday for Trick or Treating, I will sign an Executive Order rescheduling #Halloween."
3:05pm: Former ABC journalist Sarah Caddick says memories of Irene led many New Yorkers to stay put during Hurricane Sandy. .
2:50pm: How does Sandy compare to other recent massive storms?
2:46pm: The death toll is rising and is now at 13: Local officials in New York, New Jersey, Maryland, Pennsylvania, West Virginia and North Carolina reported 12 dead from the massive storm system, and Toronto police said a Canadian woman was killed by flying debris.
2:37pm: A Twitter account which appears to be run by US power company Con Edison is saying the Reuters report about workers being trapped in a Con Ed power plant is false. The account is
2:22pm: Reuters is now reporting that the Nine Mile One nuclear reactor in upstate New York has been shut down. It was not clear if the outage was related to Superstorm Sandy.
2:08pm: JUST IN: after floodwater hit its water intakes.
The alert at the Oyster Creek plant in New Jersey is the second lowest of four levels which can be defined by the US Nuclear Regulatory Commission.
2:02pm: Snapshot of the storm's impact (Reuters):
High winds and flooding hit hundreds of kilometres of Atlantic coastline while heavy snows were forecast farther inland as the centre of the storm marched westward.
The storm's wind field stretched from the Canadian border to South Carolina, and from West Virginia to a point in the Atlantic Ocean about halfway between the United States and Bermuda, easily one of the largest ever seen.
More than 3 million customers were already without power by early evening and more than 1 million people were subject to evacuation orders. Many communities have been swamped by flood waters.
1:55pm: The ABC's Michael Maher is on the banks of the Hudson River in Manhattan.
"I'm watching the water just progressively come further up the street towards me. I'm about five feet away from lapping water at the moment.
"I'd say it's probably about three feet [deep] a little further in front of me.
"It's certainly quite a frightening sight. This is the route that I walk every morning to go for a run along the Hudson and I've never seen it like this before. I've been standing here for about half an hour and in that time the water has come up this street into the centre of Manhattan by about 10 feet. So it is gradually coming into the centre of the island."
More than a million people are now confirmed to be without power in the state of New York alone.
1:45pm: The storm is now weakening as it heads inland. Also, it now appears that earlier reports of the New York Stock Exchange trading floor being flooded are actually untrue.
1:42pm: 19 workers are trapped after an explosion at a Consolidated Edison power station on the east side of Manhattan, Reuters reports.
This video shows the explosion at the plant on the East River.
1:38pm: Photo: Water pours into an underground carpark in Manhattan's financial district.
1:35pm: We've now got reports of at least 10 storm-related deaths: 5 in New York; 2 in New Jersey; 1 in Connecticut; 1 in West Virginia; 1 off the coast.
1:09pm: More from the Mayor Bloomberg press conference:
He told New Yorkers: "We will get through this like we always do."
"The worst of the weather has come. The city is feeling the impacts. At the battery we have seen record surge levels. There are extra ordinary levels of water in Lower Manhattan."
Mr Bloomberg says one of the city's main hospitals is being evacuated due to power outages.
"One thing we had not counted on was New York University Hospital's back-up power has stopped working," he said.
He says the 911 system is receiving something like 10,000 phone calls per half hour.
"Much of this is driven by non-emergency calls. Please, please, please do not call 911 if it's not a life threatening emergency," he said.
He says there are a lot of fires being caused by downed power lines.
"Stay away from windows, close the drapes, if water is coming into your home go to the highest area," he said.
1:01pm: BREAKING: Bloomberg says the worst of the weather has now passed New York and winds should be below gale force within the next few hours. He says the worst of the storm surge will soon be over.
12:57pm: BREAKING: Mayor Bloomberg is talking now: "an extraordinary" amount of water in lower Manhattan; widespread power outages; patients being evacuated from NY University Hospital after power failures; large amounts of fires caused by electrical faults. He says the 911 system is receiving 10,000 calls per half-hour. More to come.
12:56pm: We're standing by for a live press conference from New York mayor Michael Bloomberg.
12:51pm: JUST IN: US emergency officials have issued a warning for residents around Long Island Sound.
Officials say the worst of the high tide and storm surge is expected to hit in the next hour or so and people are being told to get to higher ground if they still can.
Those who are now trapped in their homes are advised to stay where they are.
"Stay away from windows. Ride this thing out. Do not try to walk through it, do not try and swim through it," an official said.
"If your house is surrounded by water right now, move to a higher level of the house."
12:49am: BREAKING: AFP is reporting that two people have been killed after a tree fell onto their car in New Jersey, according to an emergency management official.
12:45pm: In New York City right now:
There are reports that the trading floor at the New York Stock Exchange is under 1 metre of water
There are photos of water flooding into subway stations and into the construction site at Ground Zero.
12:29pm: More video from New York: this clip shows flooding at the corners of Broad and William Street.
12:15pm: This dramatic video just in: Watch the moment a giant crane buckled as high winds hit New York City earlier today. The crane was erected on a 306-metre skyscraper under construction near Times Square. Warning: contains strong language.
12:08pm: It's now clear that the Hudson and East rivers have burst their banks in New York, causing widespread flooding in lower Manhattan. There are also reports of hundreds of guests being evacuated from a hotel near the site of the crane collapse.
11:35am: BREAKING: The Wall Street Journal says at least five people have been killed in storm-related incidents in New York.
Social media is alive with pictures showing what users say is the flooding in lower New York City; the photos show cars floating in the streets. High tide is expected within 20 minutes.
11:30am: Craig McMurtrie updates ABC News 24 on the situation as night falls in Washington DC.
11:24am: Photo: A bulldozer drives through floodwaters in Brooklyn.
11:16am: New York's Fire Department says a man has been killed after a tree fell on his house in Queens.
11:09am: There are reports of widespread blackouts in New York City. This from the New York Times:
"Around 7pm the torch at the top of the Statue of Liberty, which shone all through thick daytime fog, driving rain and an early nightfall, went black.
"Soon after, lights began blinking out in buildings all over Lower Manhattan, and two flashes that looked like explosions lighted the sky above New Jersey."
11:06am: BREAKING: The US National Hurricane Centre says former hurricane Sandy has made landfall along the New Jersey coast.
11:00am: Residents outside New York City say they have been told they are "on their own" until daylight.
Linda Floyd told ABC News 24 her family was riding it out at home in the town of Maplewood in New Jersey.
"It's very dark. Winds here are shaking the homes. There are many trees down all throughout our town. Most of our town is without power," she said.
"I have a very handy Australian husband so we have a generator hooked up."
Ms Floyd says Mapletown is a commuter town about 18 miles from New York City.
"Were right in the think of the storm at the moment. There are trees down everywhere that are causing damage to homes, to garages, to powerlines," she said.
"There is a river running through our town that will flood."
She says officials have told residents "they are on their own until daylight".
10:57am: The New York Times is reporting that cars are floating in floodwaters on Wall Street in lower Manhattan.
"As the evening high tide was drawing closer, there were reports of flooding in several low-lying areas around the five boroughs, places that had not in recent memory experienced flooding," .
10:56am: DFAT has updated itstelling Australians to monitor media in the US and adhere to all warnings from officials.
The New York Fire Department says there are no injuries or people trapped at the site of the 8th Avenue Manhattan apartment building collapse.
10:51am: Some images from the US. Night has now fallen on the east coast as Sandy roars ashore.
The eye of the storm is about to hit land.
Most of Atlantic City is under water.
Lower Manhattan is flooding.
The worst of the high tide and storm surge is reportedly still to come.
10:39am: JUST IN: Twitter user @MegRobertson uploaded this picture of the apartment building which has collapsed in Manhattan.
10:37am: Lisa Millar spoke to evacuees waiting the storm out in Delaware, which is expected to bear the brunt of Sandy's fury:
10:31am: Atlantic City's public safety director says "most of the city is underwater" and parts of the city's famous boardwalk are breaking up.
Emily Previti from the Atlantic City Press Office described the scene from Atlantic City:
"It's frightening to be outside. The weather is something that most people here have never felt or seen before," she said.
"Individual property owners who are trying to hunker down... I can only imagine they're feeling very frantic."
10:21am: BREAKING: Atlantic City's public safety director says "most of the city is underwater".
On the latest weather report on ABC News24: Hurricane Sandy has now been downgraded to a "post-tropical cyclone".
10:16am: BREAKING: Wall Street is now without power.
Kristi Maroc, an Australian in New York, is at the scene of the four-storey building collapse in Manhattan:
"The front of building's gone. It looks like a doll's house, like if you've move the front off the building you can see straight into the apartment," she said.
"I'm on 8th Avenue. I'm just standing in the doorway of the building. At the moment haven't seen any ambulances. There's cranes holding up the front of the building. There's pieces of the building falling off."
10:12am: The ABC's Ben Knight is in the path of the storm in the Delaware town of Rehoboth Beach.
He is at the high school, which is doubling as a Red Cross emergency shelter.
He says people are quite calm inside but are very nervous about what is coming.
"We've got trees that are bending over. We've got horizontal rain as the gusts come through. If this is a taste of what's to come it does it appear it's going to be a very serious storm."
10:08am: BREAKING: US media is now reporting that water is flooding into the streets of lower Manhattan as the storm surge arrives.
10:04am: BREAKING: US National Hurricane Centre says Sandy will make landfall in about one hour.
10:02am: The US National Hurricane Centre says the hurricane is approximately 45 kilometres south-east of Cape May in New Jersey and is travelling west-north-west at 44kph.
There are reports a weather buoy off the coast of New Jersey has measured a wave 29 feet high.
9:59am: BREAKING: The New York Fire Department () says it is on the scene of a "multiple dwelling building collapse. The location is given as "92 8th Avenue"
9:52am: Australian Justine Bell spoke to ABC News Breakfast for a second morning as she bunkered down in New York City.
9:47am: Former ABC journalist Minsi Chung is living in New York and says the intensity of the winds and heavy rain has picked up in the past couple of hours.
9:42am: Barack Obama and Mitt Romney have put the brakes on campaigning as Sandy hits. .
9:33am: The New York Stock Exchange is now likely stay closed for a second day (Tuesday NY time).
9:30am: The US Coast Guard says it has found a missing crew member "unresponsive" off the North Carolina coast after the HMS Bounty sank overnight.
The search is continuing for the captain who is also missing.
9:18am: North America correspondent Lisa Millar is reporting from an evacuation centre in Delaware, where 200 people are taking shelter.
She says many people were ordered out of their homes and told they had to be at the evacuation centre and off the roads by 3:00pm (local time), before conditions became too dangerous to be outside.
Millar says there have been several medical emergencies at the centre but there are doctors, nurses and military officials also sheltering at there.
"It's getting dark. It's coming into night time. We're not feeling the full brunt of it yet. It's going to last many hours and it's going to be a long night," she said.
9:17am: New York mayor Michael Bloomberg has warned residents to stay away from the buckled crane which is dangling precariously above apartment blocks.
"Why it happened at this point nobody knows. You don't need to have somebody going out there to find out why, you don't need to lose a life," he said.
9:12am: Qantas has just announced that it has cancelled today's flights to LA and New York; the flight numbers are QF 107 and QF 108.
9:10am: There's now YouTube video of the crane which has toppled over on a 90-storey high rise near Times Square, NYC.
9:05am: The US Coast Guard has released video of the rescue of 14 crew members from the HMS Bounty replica tall ship. Two crew are still missing.
9:00am: The state of emergency currently extends across nine states. They are: Connecticut; Delaware; Maryland; New Jersey; New York; Pennsylvania; Rhode Island; Virginia; West Virginia.
8:47am: New York Mayor Michael Bloomberg has just given a press conference.
He told New Yorkers that the worst of the storm was about to hit the city and said the time for evacuation had now passed.
"As everybody knows we're already seeing significant impacts from the storm and the worst of it is about to hit. I think we have done all we can to prepare.
"Now as the storm intensifies the most important thing I can say is if you're in your home or somewhere safe where you can remain, stay there. The time for relocation or evacuation is over. Conditions outside are dangerous and they're only going to get worse in the hours ahead."
In other key developments this morning:
President Barack Obama has warned there could be fatalities from the massive storm, and has declared emergencies in nine states.
Up to 750,000 people are without power in New York and New Jersey and seaside communities have already started flooding as the storm nears the coast.
Sandy is likely to make landfall near Atlantic City, New Jersey, in a few hours.
New York has been shut down, with almost 400,000 residents ordered to evacuate, the Stock Exchange closed, and public transport and flights cancelled.
A crane on the top of a 90-storey New York apartment block has buckled over in the gale-force winds.
10,000 flights have been cancelled.
Both Barack Obama and Mitt Romney , just eight days out from the presidential election.
© ABC 2012
01:42 EDT Parts of Sydney have been lashed by a storm on Monday afternoon which resulted in ambulance crews treating several people who were struck by lightning.