East Coast Takes a Beating as Sandy Nears Landfall
Forecasters say Sandy is "moving quickly" and should make landfall by around 8pm ET Monday in southern New Jersey or Delaware.

In its 7pm ET update, the National Hurricane Center downgraded the storm to a post-tropical cyclone and said it's losing strength but the storm still has sustained winds of 85 mph.

The eye has almost made landfall and is headed for New Jersey and Delaware.

Sandy was set to collide with a wintry storm from the west and cold air streaming down from the Arctic. The combination superstorm could menace some 50 million people in the most heavily populated corridor in the nation, from the East Coast to the Great Lakes.

New York City Mayor Michael Bloomberg told residents Monday evening to "stay put" and that the time for evacuation and relocation was over. Con Edison, the power company, has also shut down power in parts of lower Manhattan to lessen damage from flooding sea waters.

New Jersey's famously blunt Gov. Chris Christie also issued a warning to those who didn't evacuate as ordered. "For those who are on the barrier islands who decided it was a better idea to wait this out than to evacuate, for those elected officials who decided to ignore my admonition, this is now your responsibility," he said Monday evening.

"If you're still able to hear me, we need you to hunker down and get to the highest point possible in the dwelling that you are in. We will not be able to come help you until daylight tomorrow."

More than a million customers already were without power by early evening Monday and millions more could lose electricity. One disaster forecasting company predicted economic losses could ultimately reach $20 billion, only half of it insured.

All U.S. stock markets were closed on Monday and will remain closed on Tuesday, according to a NYSE Euronext statement. This marks the first weather-related closure for the markets in 27 years.

The company plans to re-open the markets on Wednesday "conditions permitting" and will provide further updates on Tuesday.

The hurricane-force winds blew over a construction crane on top of a luxury high-rise building in Manhattan, leaving the crane dangling off the edge of the building. The incident, at a building called One57 on West 57th Street, prompted a huge emergency response. New York City officials ordered people in neighboring buildings to move to lower floors.

The building is known as one of the priciest ever in New York. A six-bedroom penthouse at the building is under contract for a reported $90 million. The building recently made headlines for tax breaks from a program aimed at low-income housing. (Read more: Billionaires Get 'Low-Income' Tax Breaks in Condo Tower)

The superstorm could endanger 50 million people in the most heavily populated corridor in the nation, with forecasters warning that the New York area could get the worst of it — an 11-foot wall of water.

State governors warned of the acute danger from the winds and torrential rains.

"There will undoubtedly be some deaths that are caused by the intensity of this storm, by the floods, by the tidal surge, by the waves. The more responsibly citizens act, the fewer people will die," Maryland Governor Martin O'Malley told reporters.

He added that the storm's impact on the state will be much more severe than previously thought just 24 hours ago.

President Barack Obama declared emergencies in several states including Massachusetts, Connecticut, Rhode Island, New York, New Jersey, and Pennsylvania, authorizing federal relief work to begin well ahead of time. He promised the government would "respond big and respond fast" to states and cities after the storm hits.