So Tishman Speyer Properties says its joint venture with BlackRock Inc. will let the lenders take over Stuyvesant Town-Peter Cooper Village, the mammoth New York City apartment complex acquired for $5.4 billion at the height of the real estate bubble and now worth maybe a third of that.

The idea sounds simple enough: Throw the keys on the table and walk away. The reality is anything but. For starters, who exactly gets those keys -- or, more precisely, the title? Move on to inevitable creditor disputes. Factor in everything from borrower guarantees to which of the dozens -- hundreds? -- of lenders are in the money and which aren't.

The result is a colossal mess that's almost certain to generate multiple lawsuits. Don't count out the possibility of bankruptcy.

Stuyvesant Town is big and unwieldy, but its problems aren't at all unique. A real estate lawyer called the Speyer-BlackRock investment a slow-motion train wreck in which just about everyone saw disaster coming months before the announcement. The same can be said of commercial real estate in general.

Securitization is at the heart of this matter. Financing for Stuyvesant Town was underwritten in 2006 by a $3 billion mortgage that was then securitized. By their very nature, commercial mortgage-backed securities are widely distributed and held, making workouts extremely difficult. The U.S.-government-owned agencies Fannie Mae and Freddie Mac are the biggest holders of Stuyvesant Town CMBS, according to reports.

The Stuyvesant Town project is further complicated by $1.4 billion in mezzanine debt. Given Fitch Ratings' October estimate that the properties are now worth only $1.8 billion, mezzanine loans appear to be completely out of the money. But many lenders aren't likely to give up without a fight. After all, they have nothing to lose.

There isn't much track record for consensual foreclosures in such complex transactions, and what there is should give pause. Last May, hotels property owner Extended Stay Inc. reached an out-of-court agreement on about $3 billion in CMBS. Some junior mezzanine debt holders didn't like the terms, went to court and obtained a temporary restraining order on the workout. The following month, Extended Stay was forced to file for Chapter 11.