Hurricane Sandy has passed, but the process of picking up the pieces has only just begun.

The storm is the worst ever to affect commercial real estate’s largest market. And there is extensive damage up and down the East Coast with Atlantic City’s casinos being some of the worst-hit properties.

In New York, the nation’s largest public transportation system is largely offline. Some bus service was restored today. Subway service will begin to come online tomorrow, but full service may not be back for days or weeks.

“The New York City subway system is 108 years old, but it has never faced a disaster as devastating as last night,” said Joe Lhota, chairman of the Metropolitan Transit Authority, this morning.

In addition, New York’s airports were hard hit. JFK International and Newark Liberty International airports began limited service today. LaGuardia Airport, which was flooded, is closed indefinitely. As a result, thousands of lights have been canceled.

And power remains out below 38th Street for much of Manhattan (including at NREI’s offices in Chelsea). It may not be restored for several more days according to Con Edison.

Initial estimates are that damages may be in the order of $20 billion with between $10 billion and $30 billion in lost business. That ranks as one of the most damaging storms in U.S. history, but less than the estimated $100 billion in damages that resulted from Hurricane Katrina in 2005.

The worst damage to commercial real estate in New York was in downtown where a 13-foot storm surge swept through lower Manhattan and the Lower East Side. The World Trade Center construction site was flooded as well as many underground structures throughout the financial district.

Details on the full extent of the effects of the storm have yet to emerge. But here is roundup of initial impressions.

Crane Collapse at One57

As Hurricane Sandy bore down on New York City on Monday, the boom of a crane at the One57 building in Midtown collapsed.

The construction site of the under-construction 90-story luxury apartment tower is located at 57th Street and 6th Avenue. As of Tuesday, part of the crane was dangling off the building, 75 stories above the ground.

Atlantic City Casinos and Resorts Devastated

The eye of the storm made landfall directly over Atlantic City, N.J. and the storm left behind damage and flooding.

"Water damage, broken windows, some roof damage," Jan Jones, executive vice president of Caesars Entertainment Communications & Government Relations, told KOLOTV news in Nevada. "The good news is much of he damage was way more limited than we expected.”

There are 12 casino resorts in Atlantic City. They are running on emergency power, but have been closed for several days. The casinos lose $5 million for every day they are not open.

"We anticipate being able to open up no later than Friday, and hopefully we'll be able to offer customers and some of the residents and citizens of New Jersey an opportunity to relax and get away from the havoc and trouble that's been caused by this storm," Tony Rodio, CEO of the Tropicana in Atlantic City told FOX5.

The impact on REITs

SNL Financial issued a report analyzing the potential impact on REITs.

According to SNL’s analysis, “Alexander's Inc. leads the way among publicly traded REITs in regard to portfolio exposure in the area, with 100 percent of its primarily retail portfolio there. First Real Estate Investment Trust of New Jersey is second on the list, with 81 percent of its portfolio in the New York-Northern New Jersey-Long Island, NY-NJ-PA MSA. Its portfolio there comprises eight multifamily properties and five additional retail assets. Three out of four properties in Gyrodyne Co. of America Inc.'s portfolio are in the area. Two of the three assets are medical office buildings and one is an industrial asset. The average total occupancy of the three is 88 percent. Mack-Cali Realty Corp. and SL Green Realty Corp. round out the top five U.S. REITs in terms of exposure to the New York City metro region, with 68 percent and 63 percent of the companies' respective portfolios there.”

According to SNL, REITs own more than 1,600 properties in the affected area. REITs own 309 office assets, 217 self-storage assets, 169 shopping center assets and 138 multifamily assets in the area.

CMBS Delayed

According to the Wall Street Journal, $3 billion in CMBS issuances were delayed as a result of the storm.

According to the WSJ, “The delays, including a $1.05 billion bond backed by the Blackstone Group’s Motel 6 hotel portfolio, come as demand for the securities has spurred a resurgence in commercial real estate lending and securitization. The deal is led byJ.P. Morgan Chase & Co. and Deutsche Bank.”

Other CMBS pricings delayed were the $835 million refinancing of a loan on Las Vegas’ Fashion Show Mall from and at least $889 million in securities backed by 48 loans from Deutsche Bank and Cantor Fitzgerald, the investors said.