The rating on Chicago Public Building Commission Ill.'s bonds, issued for Cook County Community College District No. 508, is based on an escrow made up of U.S. Treasury obligations, and state and local government series, which are sufficient to pay the bonds through their Jan. 1, 2007 maturity date. The escrow originated in 1990 to pay debt service through maturity on the commission's refunded series 1987B bonds, which were legally defeased by the commission with a reserved right to call the bonds at some future date. The series 1987B bonds were issued by the commission for various capital projects for the Cook County Community College District. Most of the series 1996 bond proceeds will be used to establish an escrow
