Sunwest Management, Inc., the fourth largest provider of senior housing in the United States, owes $1.8 billion to its creditors and filed for bankruptcy for 10 centers (located in North Carolina, Oregon, South Carolina, and Tennessee) while its creditors have begun foreclosure proceedings against affiliated companies.  The company blames the housing and credit crises, but some experts say that Sunwest overbuilt.  Since 2005, the company nearly doubled its portfolio, adding 124 retirement centers.  Sunwest now has 275 facilities and 12,000 employees.  Last summer, it put 132 facilities on the market in efforts to raise $500 million.  Jeff Manning, "Sunwest tries to assure residents it is financially sound," The Oregonian (Aug. 25, 2008); Jeff Manning and Julie Sullivan, "Growth strategy costs assisted living provider: Experts trace Salem-based Sunwest's troubles to rapid expansion, not just the housing and credit crises," The Oregonian (Aug 26, 2008).