Where the damage to property began prior to the purchase of general commercial liability policy, a clause in the policy excluded coverage, even though damage was unknown at time of purchase.The 7th U.S. Circuit Court of Appeals affirmed a decision by U.S. Magistrate Judge John E. Martin, Northern District of Indiana.Juan and Maria Garcia purchased commercial property at 2316 Ripley St., Lake Station, Ind., in August 2004. The Garcias insured their property with a policy from Atlantic Casualty Insurance Co.During the …