(Canby, OR)  --  Five people are dead including an infant following a domestic violence situation in Clackamas County.  Police say 42-year-old Mark Leo Gregory Gago killed the infant and three adults at a home near Canby overnight Saturday and was about to kill a little girl when responding officers opened fire, killing him.  It's not yet clear what type of weapon Gago was using, but a witness tells KATU that one victim got away after wrestling an "ax-type" weapon from him.  Police say two victims survived the attack.  Police are identifying the deceased victims as nine-month-old Olivia Lynn Rose Gago, 31-year-old Shaina Sweitzer, 66-year-old Jerry Bremer and 64-year-old Pamela Bremer.