The so-called Frankenstorm made landfall on the US east coast overnight, coming ashore in New Jersey and bursting the banks of the East and Hudson rivers, submerging New York's road and subway tunnels.

New York's Metropolitan Transportation Authority described the event as the worst disaster in the history of the NYC subway system.

Several major commuter subway tunnels under the East River in New York City could be closed for at least four days, according to MTA spokesperson Kevin Ortiz. In the next few days officials will need to assess the flood damage and pump the water out before trains can be started up again, he adds.

Officials at Consolidated Edison say it could be up to a week before power is fully restored in NYC after a sub-station exploded, blacking out downtown Manhattan. The company said 670,000 customers were without power in New York City and Westchester, with 230,000 of those in Manhattan alone.



In the financial district, major banks shifted their dealing operations to back-up trading desks away from the eye of the storm and prepared contingency plans to use spare capacity in Europe and Asia. In the retail markets, the nation's banks were also well-prepared: ATM stocks were replenished to avoid a cash crunch and branches in Sandy's path were closed in advance.

Nyse and Nasdaq OMX are expecting to resume normal trading on Wednesday when the full extent of the damage has been assessed. In the interim, all US equities, bonds, options and derivatives markets will remain closed. Thomson Reuters and Sungard, who were among a host of companies to postpone their quarterly earnings announcements, say they will post their results Wednesday.