The Kushner Companies bought the building in January 2007, closing the deal on Jared Kushner's birthday and paying the highest price ever for a New York office building. "This is a great acquisition for our company," Jared Kushner said at the time.

According to the Kushners, they put $500 million into the purchase. They then took out a mortgage and hundreds of millions in additional loans to cover the purchase price and ancillary costs.

The building represented a new beginning for a New Jersey real estate family that had specialized in suburban garden apartments. The Kushner Companies moved its headquarters to the 15th floor on Fifth Avenue, from Florham Park, N.J.

While the total paid for the building was not that much higher than the previous record -- $1.72 billion for the MetLife Building -- the price for MetLife worked out to about $600 a square foot, while the Kushners paid $1,200 a square foot for 666 Fifth Avenue.

Even at the time, income from the building, which was almost completely rented, covered only about two-thirds of the annual debt payments, according to records.

Then, as the 2008 financial crisis set in, rents, instead of going up, went down. To pay off some of their debt, the Kushners began selling parts of the building, including its most valuable asset, the retail space on Fifth Avenue, to the Carlyle Group and Crown Acquisitions for $525 million, a remarkable price. The proceeds were used to pay off secondary loans on the building, not the main mortgage.

But the bleeding continued. Two years later, with the tower's reserve funds nearly exhausted and the owner losing as much as $30 million, the mortgage holder appointed a "special servicer" to oversee 666 Fifth Avenue. Such a company manages a property loan when the borrower is in danger of falling into default.

The Kushner Companies renegotiated the terms of the loan in 2011.