It was one of the most major deals of all times and it was consummated at the height of the market in 2006 — the $5.4 billion acquisition of the sprawling Peter Cooper Village and Stuyvesant Town apartment complex in Manhattan. Now the deal is likely to go down in history as one of the largest defaults — $4.4 billion in debt.

Now investors and lenders are assessing the fallout. According to the New York Times:

Yet in walking away, the partners, Tishman Speyer Properties and BlackRock Realty, have left tenants in limbo and other investors with far bigger losses.

Many of the other companies, banks, countries and pension funds — including the government of Singapore, the Church of England, the Manhattan real estate concern SL Green, and Fortress Investment Groups — that invested billions of dollars in the 2006 deal stand to lose their entire stake.

And according to WSJ, the biggest question on the table is who takes control of the property:

The leading contender to get initial control is CW Capital, a servicer that represents the investors who hold the $3 billion first mortgage on the property. That mortgage was packaged into commercial mortgage-backed securities known as CMBS. But the property’s debt structure is complicated and others are likely to push for control, including possibly the thousands of residents of the more than 50-year-old complex.

In addition to the first mortgage, there is $1.4 billion of junior, or “mezzanine,” debt on the property and some holders of that debt have also been maneuvering for control in recent weeks. Some junior creditors may try to replace the Tishman venture as owners by agreeing to pay the debt service on the first mortgage. If CW Capital takes over, the mezzanine investors likely will suffer a big loss.

Now the question is, “who will take the keys on behalf of which level of debt,” said Mark Edelstein, head of the real-estate group at law firm Morrison & Foerster LLP. According to a person familiar with the situation, the Tishman venture has reached out to CW Capital to start the property-transfer process.