Superstorm Sandy lost its hurricane status before it pounded the US east coast Monday night (early Tuesday India time), but not its ferocity.
Fierce winds and heavy rains left 20 people dead, knocked out power to huge swathes of the country's most densely populated region and left
the New York Stock Exchange shut for second straight day - a first since 1888.
President Barack Obama declared a "major disaster" in New York state and New Jersey as more than eight million Americans Tuesday woke up to a blackout and deadly devastation caused by the once-in-a-generation storm.
All along the eastern seaboard, Sandy left a trail of destruction - homes underwater, trees toppled and power lines downed.
Government offices and public transport were shut. More than 16,000 flights have been cancelled since Sunday.
Early estimates have put the damage to property between $10bn and $20bn.
Death toll is expected to rise as many people are missing. Ten of the dead were in New York City alone. Sandy killed 65 people before hitting the US -- 51 in Haiti.
The National Hurricane Center said Sandy had weakened early Tuesday as it moved inland, but could still generate gale-force winds and flooding along the eastern coast.
Obama cancelled a campaign trip to vital swing-state Ohio on Wednesday to stay at the White House to manage the response, his spokesman said.
The superstorm was so enormous that commander of the International Space Station Sunita Williams said she and crew were able to make out the big swirl at the centre of Sandy as it neared land.
Though dropped just below hurricane status before making landfall in New Jersey, the 'Frankenstorm' wreaked havoc on the New York City subway system, flooding tunnels, garages and rail yards and threatening to paralyse the country's largest mass-transit system for days.
For most of Monday night parts of a wind-tossed construction crane dangling precariously over a congested New York City neighbourhood came to represent the storm.
One of those stuck in a New York high-rise residential unit without power was industrialist Anand Mahindra's daughter.
"Mercifully, daughter's in a no flood zone of lower manhattan. But building windows are shattering, residents are in the lobby&power's gone," he tweeted.
Lower Manhattan, in fact, did get flooded.
With agency inputs