(Oregon City, OR)  --  An Oregon City couple is under investigation, following the death of their newborn daughter.  Authorities say 24-year-old Sarah Mitchell gave birth Sunday to two girls at her parents' home on South Lodger Road, and one of them developed respiratory problems.  Officials say no one called 911 when the problems became evident and the infant died.  Sarah and her husband, 21-year-old Travis Lee Mitchell, who are members of the Followers of Christ Church in Oregon City, are being investigated.  Deputies say the surviving infant is in the Neonatal Intensive Care Unit at Oregon Health & Science University.