Bertha Sieg RESOLVED Bertha, circa 1994 Missing Since 02/08/1994 Missing From Duncanville, Texas Classification Endangered Missing Sex Female Race Hispanic Age 14 years old Distinguishing Characteristics Hispanic female. Details of Disappearance Bertha disappeared from Duncanville, Texas on February 8, 1994. In June 2016, she was found deceased. Further details are unavailable. Investigating Agency - Source Information The National Center for Missing and Exploited Children . .