Wall Street worries about commercial real estate implosion 

After getting battered by the housing market, Wall Street firms now expect the weakening economy will take its toll on the commercial real estate market. Analysts at Goldman Sachs project a commercial decline of 21 to 26 percent over the next two years. Default rates on commercial mortgage-backed securities are low for now, at just 0.4 percent, but are expected to increase, thanks to loose lending during the boom. Rising commercial property values were fueled in part by commercial mortgage-backed securities, which saw a tripling in volume from 2003 to 2007.