Reporters: Pia Gadkari and Tom Geoghegan @abzik89, from Manhattan, NY, tweets: Man, #sandy is getting serious
https://twitter.com/hashtag/sandyHurricane Sandy is closing in on highly populated areas of the US east coast, threatening storm surges and devastating flooding.
New York's Governor Andrew Cuomo tweets: The Robert F. Kennedy/Triborough Bridge will stay open as long as consistent with safety #Sandy
1746: Governor Christie said he spoke on the phone to Mr Obama this afternoon, and the president said if the New Jersey governor needed anything from the federal government, to call him directly
Jallah Kennedy, in Galloway, New Jersey, emails: The wind is becoming heavier. Power and heating has just returned a few minutes ago. My family of 10 is still expecting the worst. When the actual landfall arrives, we are prepared to evacuate, provided flooding does not hold us back. Not sure though where we will go.
1742: New Jersey's Governor Chris Christie says in a press conference that evacuations are now suspended, due to safety concerns. Hurricane Sandy expected to hit Atlantic City in an hour, he says.
1732: As evening closes in, visibility reduces as rain and wind intensify in Marshfield, Massachusetts
1728: The National Hurricane Center has discontinued its tropical storm warnings for the state of North Carolina, but the area is still designated as "hazardous".
@arraaaffff, tweets: Praying for my brother in Maryland and my family on the Jersey Shore. #staysafe
Andrew Cuomo, New York Governor tweets: Hurricane #Sandy Helpline: 1-888-769-7243
Paul Johnson, in New York, emails: We're on holiday in New York staying just a couple of blocks away from the collapsing crane! The streets around the crane have been closed off by the police and lots of people are looking on and taking photos - despite the instructions to stay inside with the blackout curtains closed.
1713: The National Hurricane Center has just issued its 17:00 EDT (21:00 GMT) update, which shows Hurricane Sandy is just 40 miles (65km) off the coast of Atlantic City now. Maximum sustained wind speeds remain high, at 90mph (150km/h).
1704: In New York City, rising wind speeds could mean bridges are closed earlier than 19:00 EDT (23:00 GMT), the governor has tweeted. @SlaterJ13, tweets: Praying my family in New York, New Jersey and Long Island are okay #prayersfortheeastcoast
1659: For more information, we've put together this list of useful links to help you prepare for Hurricane Sandy. And there's this Twitter page for the latest updates.
The Weather Channel tweets: Atlantic City's public safety director says most of city under water.
1646: Public schools will remain shut on Tuesday in New York City, Philadelphia and Washington DC on account of the hurricane. In Washington, the metro will not operate either.
1644: Not sure if the hurricane picture you just saw on your favourite social network is genuine? Mashable has collated 5 Fake Hurricane Sandy Photos You're Sharing on Social Media which features some of the most common examples.
1639: In an updated advisory from the National Hurricane Center, Sandy is now 65 miles (105km) away from Atlantic City, and has maximum sustained winds of 90mph (150km/h). The NHC estimates that the centre of Sandy could reach the coast of southern New Jersey or central Delaware within the next three to five hours.
1636: The New York governor earlier announced the Tappan Zee Bridge was closing. He has now said the following bridges will also shut at 19:00 EDT (23:00 GMT): George Washington, Verrazano-Narrows, Throgs Neck, Whitestone, Henry Hudson and Cross Bay Veterans.
1625: Officials issue a final evacuation warning to residents that have not followed mandatory evacuation notices - leave now. We are approaching the hour where it will not be possible to evacuate, officials say.
1623: Governor Cuomo says the worst of the storm has not yet hit New York. The first high tide on Tuesday morning will also be dangerous, and residents need to remain vigilant throughout the night, he says.
1613: The city of Baltimore in Maryland has banned all vehicle travel from 6pm until noon on Tuesday, except for hospital and emergency vehicles.
1607: Here is a picture of beach homes in New York's Shinnecock Hills, in an exposed part of Long Island, as powerful waves beat the shore.
1605: New York Governor Andrew Cuomo has called another news briefing, and officials are saying the hurricane is approaching a little faster than expected. They say coastal areas such as Nassau County can expect to see storm surge, rain and winds intensify as the afternoon draws on, peaking around 18:00 EDT (22:00 GMT) around high tide.
Jake Tapper, ABC News White House correspondent tweets: Dept of Energy: As of 2pm EDT, the impacted states report a total of 316,563 customers without power in the affected areas. Massachusetts Governor Deval Patrick No serious damage or injuries reported yet.
1543: The Reuters news agency is reporting that Consolidated Edison, a major utility provider in New York City, is warning customers it may shut down power for lower Manhattan on Monday evening. The blackout could extend as far north as 34th Street, but would only affect avenues close to the Hudson and East River, and near the tip of the island, a spokeswoman said.
1535: That makes a total of eight states, plus the District of Columbia, that are to receive federal emergency funds.
1533: President Obama has now signed a declaration of emergency for the state of Delaware, clearing the way for federal aid to assist the response and recovery efforts to Hurricane Sandy.
1529: New York Governor Andrew Cuomo has announced that the Tappan Zee Bridge across the Hudson River will close at 16:00 EDT (20:00 GMT).
1525: Officials are warning residents to stay indoors. Some people are still on the streets, but in Baltimore rising winds seem to be making it harder to get around.
1517: Matthew Wells, in Brooklyn, New York says New York Public Radio is reporting that 10,000 people are already without power around the city. The wind is picking up outside, slowly but surely.
1511: There are 3,500 residents left with no way off the island of Chincoteague, Virginia. The water is reported to be 3ft (90cm) deep in some places and there is no emergency shelter. Officials imposed a noon curfew and have told everyone to stay indoors.
1511: Reports of flood damage are coming in from other parts of the East Coast. The tiny, 37-square-mile island of Chincoteague, Virginia, is under water, the Associated Press has reported.
1508: Lt Kevin Sullivan told the BBC the ship capsized as the crew were getting into life rafts. "They had to swim clear of the boat and try to get in the life rafts from there." The search goes on for the missing two.
1507: Now an update on what happened when the 16-strong crew of the replica tall ship HMS Bounty abandoned ship off the N Carolina coast. Two crew are still missing.
1505: This picture shows that incident in more detail. The arm of the crane appears to have snapped, leaving it dangling above West 57th Street. No injuries are reported and the Fire Dept is attending.
1458: In the middle of New York's densely populated Midtown neighbourhood, CNN's Piers Morgan has reported that a crane has snapped under the force of driving winds. The storm is still several hours away from the mainland and conditions are expected to deteriorate as the day goes on.
1455: Earlier on Monday both Barack Obama and Mitt Romney cancelled campaign events on account of the storm. Now, Maryland Governor Martin O'Malley has suspended early voting on Tuesday.
1454: With the presidential election looming next week, some political commentators have been asking what the impact of Hurricane Sandy might be on the race for the White House.
1453: As the water level advances in New York, local radio station WNYC have created this flood gauge watch with information across the region impacted by Sandy.
Laura Trevelyan BBC News, New York tweets: #Sandy wind howling beneath manhattan bridge. We are pulling back to a more sheltered location.
Arthur Varanelli, South Dennis, Massachusetts writes: "Watching and feeling the wind gusts coming off the Atlantic and Massachusetts Bay onto Cape Cod, it has become very clear that Sandy is a very, very serious storm. The wind is forecast now to worsen until late afternoon, but even that can become unpredictable."
The National Oceanic and Atmospheric Administration tweets: RT @NOAASatellites: #Sandy is moving toward NJ shore more quickly: See our animated imagery:
http://go.usa.gov/Yvuw1439: The BBC has put together a series of graphics to help illustrate the immense size of the storm system. We've also got a timelapse from Nasa of the hurricane as it tracks towards the East Coast.
1437: In and around Philadelphia, utilities companies are now reporting that tens of thousands of people have lost power, according to the Philadelphia Inquirer. An estimated combined total of 62,000 outages have been reported by PECO, Atlantic City Electric, PSE&G, Delmarva Power & Light, and PPL Electric, the newspaper says.
1428: Waterfront properties are being damaged at Ocean City in Maryland, says CNN's Sandra Endo, reporting from the very windswept beach. The wind and rain are relentless, she adds.
Ewan Baird in New York posted this photo on Twitter, commenting: "@BBC_HaveYourSay @bbcnewsbeat getting wetter here in NYC #Sandy"
1418: So we have tunnels from Manhattan to New Jersey and Brooklyn shut now. Boston is also closing its subway, bus and train network now. Public transit systems were closed earlier on Monday in Washington DC, New York City and Philadelphia.
1417: More from the National Hurricane Center. Sandy is moving forward at 28mph (44km/h) with maximum sustained winds of 90mph (150km/h), with hurricane force winds expected across a wide swathe of the US East Coast - between Chincoteague, Virginia, and Chatham, Massachusetts.
1409: The National Hurricane Center is out with its 14:00 EDT (18:00 GMT) update: Hurricane Sandy is closing in on Atlantic City, it is now 110 miles (180 km) offshore, 175 miles (285 km) south-east of New York City.
1407: Laura Trevelyan BBC News, New York The Holland Tunnel and Brooklyn Battery Tunnel have just closed, and officials are warning residents in evacuation zones to get out now, just hours before Sandy makes landfall.
1402: Earlier on Monday, we heard from US President Barack Obama, who warned the public to follow instructions from state and local officials and act quickly. New York Mayor Bloomberg also sent a message to New Yorkers, asking them to evacuate promptly.
Edward Henry in Somerville, Massachusetts writes: "I live across the river from Boston. It is still early; we're being told the worst is yet to come. So far lots of strong wind gusts all morning, rain off and on. The wind is getting stronger now. The whole Boston area public transit network is shutting down in 10 minutes."
1357: The storm could affect up to 50 million people in the densely populated region, and is likely to last through the day on Tuesday.
1356: This huge, late-season storm is colliding with a cold front moving south from Canada and is expected to result in blizzard conditions as far inland as West Virginia.
1355: For those just joining us now, to recap - Hurricane Sandy is approaching the US East Coast, expected to make landfall in the state of New Jersey on Monday evening.
1353: Trying to travel today? Airports up and down the East Coast are experiencing major delays and cancellations, with more than 7,000 flights affected by the hurricane. The Federal Aviation Administration has created a searchable map of airports in the region, with information about service conditions.
1352: We've also got a collection of stories from East Coast residents facing the storm.
1339: The New York Stock Exchange has now confirmed it will stay shut tomorrow, as the storm ploughs through. It is aiming to re-open on Wednesday.
1331: This detailed timeline from #HurricaneHackers, a crowdsourced information and resource platform on Hurricane Sandy, shows that electricity has been shut off in some parts of New York's Zone A evacuation area. Storm surge has been reported in southern New York City neighbourhoods - Red Hook, Brooklyn and Battery Park, Manhattan.
1327: Jennifer Davis of Fox News, Norfolk, Virginia says the storm surge could be four to six feet above normal levels and there are serious concerns about flooding.
1325: Storm surge is expected to peak this evening, during high tide
New York Governor Andrew Cuomo tweets: #Sandy tip: Keep curtains & blinds closed. Do not be fooled if there is a lull; it could be the eye of the storm - winds will pick up again
1316: With East Coast cities rushing to prepare for Sandy to arrive, this map pinpoints the location of ships as they move towards safe waters ahead of the storm.
Catherine Kadar in New York City tweets: "Winds gusting up to 30 MPH in my neighborhood and Sandy isn't even nearby yet. Scary #Sandy"
1304: As Sandy approaches, the resort towns along the New Jersey shoreline are bearing the brunt of the hurricane's force. A real estate agent in Sea Isle is updating his website with images of flooded properties and streets.
Linda Poke in Tewkesbury, Gloucestershire writes: "My 17-year-old son and his classmates are on an American exchange in New York. They were due to fly home today, but obviously their flight has been cancelled. Would like to wish them all well and say a huge thank you to their lovely American host families who still have them in their homes. God willing they'll be home soon."
1257: New Jersey local media are receiving reports that waves are topping 20ft (6m), and storm surge is expected to get worse during high tide, plus a full moon coinciding with the arrival of the hurricane is expected to increase tidal intensity. The next high tide is expected at about 19:30 EDT (23:30 GMT).
1254: The president only answers one question - what effect the hurricane may have on the election. Mr Obama says the election will "work itself out" next week, and his immediate concern is for families and first responders.
1252: Everybody is taking this very seriously, the president adds. Look at the government's website on how to prepare for the storm if you need more information, he says.
1250: It may take time for any power outages to be fixed, says the president.
1250: The president says the good news is that officials have had a few days to prepare for the onset of the storm. But members of the public will be putting first responders in harm's way if they do not leave when told to, he says.
1249: We are making sure food, water and emergency power generation is available, Mr Obama adds. He says his most important message to the public is to follow instructions from your state and local officials, and act quickly.
1247: President Barack Obama speaking now. "This is going to be a big and powerful storm."
1247: The BBC's Laura Trevelyan tweets: #sandy alarming down here on the waterfront between the Brooklyn and Manhattan bridges - very strong winds, trees bending over
Emma Lewis from London emails: "I'm on holiday, currently holed up in a hotel in Providence, Rhode Island. It's already incredibly windy here, but the rain isn't too bad yet, just a heavy drizzle. Went for a walk around earlier and buses are still running but the streets are pretty deserted otherwise and all of the shops are closed."
1243: NYC Mayor's Office tweets: If you are still in Zone A and have a way to get out, leave IMMEDIATELY. Conditions are quickly getting worse. #Sandy. The mayor's office has produced this map to let you know if you're in Zone A.
1231: If you are trying to locate emergency resources on the East Coast, Google has compiled this handy map.
1229: New Jersey Governor Chris Christie also addresses children staying at home today: "There is no reason to be scared. Adults are taking care of business."
1221: We're hearing from the New Jersey Governor Chris Christie now. He tells residents to go to their county shelters if they need to leave their homes, and to use this website to find their closest centres. He emphasises the need to remain calm, but also to follow instructions and take precautions to avoid loss of life.
1219: Clementine in Teeside, UK texts: "My family live just outside Ocean City, Maryland and are one of the few homes still to have electricity. Just waiting for it to happen is the worst. Prayers with you all."
BBC Weather @bbcweather #Sandy has strengthened today. Winds will cause problems but bigger issue will be flooding from heavy rain & massive storm surge
1215: Meanwhile, President Obama has signed emergency declarations for Maryland, Massachusetts, New York, New Jersey, Connecticut, Pennsylvania, Rhode Island and the District of Columbia, according to the White House.This paves the way for federal assistance with preparations and recovery. The BBC's Jonny Dymond tweets: #Romney events Monday and Tuesday cancelled. #Sandy wreaking havoc on final week of campaign. @BBCNewsUS
1203: Sonia Heaton in New York writes: I'm on holiday staying in an apartment in Wall Street. The apartment manager has just told us the electricity and water will be shut off at 2pm, having told us yesterday that electricity wouldn't be a problem because of the back-up generator. I've been out looking for torches but the only shops open are sold out.
1159: Water levels are rising in New York City - streets in the borough of Queens are now under water.
The Maryland emergency services tweeted: Cannot stress this enough! @governoromalley: We're urging everyone except first responders and essential personnel to stay off the roads.
1153: Earlier, Maryland Governor Martin O'Malley gave a gloomy forecast of the impact of the hurricane for his state. "There will be people who die and are killed in this storm," he said.
1151: Sandy's wind speeds are picking up, the latest forecasts say, with sustained speeds of 90 mph (145km) as it approaches the US mainland.
1149: Mark in Brooklyn, New York emails: I've been living in Brooklyn for six years after moving from England. New York City's response to this situation is very impressive. Very organised and very proactive. People taking it very seriously. We are all preparing for the worst and hoping for the best.
1148: With Hurricane Sandy still several hours away from making landfall, the pier in Ocean City, Maryland, has suffered significant damage, the Baltimore Sun reports, after being battered by rough waves overnight.
1143: New York Mayor Michael Bloomberg is giving a press conference now. He says the greatest danger to New York is likely to come from storm surge and coastal flooding, but that the storm is expected to change from a hurricane to a "Nor'easter" - ferocious blizzards that strike the north-eastern US in the winter - as it heads inland, and this could have significant implications for the city.
1138: Despite the worsening weather conditions across the East Coast, the changing of the guard at the tomb of the unknown soldier, at Arlington Cemetery, Virginia, continues uninterrupted.
1134: The Reuters news agency is reporting that the New York Stock Exchange, which is closed, might remain shut on Tuesday as Hurricane Sandy continues to barrel over New York City. This is the first time the markets have closed on account of the weather in 27 years, it says.
1132: For more information, we've put together this list of useful links to help you prepare for Hurricane Sandy.
1123: Derrick Chen sent in this image of the New York Stock Exchange making ready for the arrival of Hurricane Sandy with sandbags.