(Belfair, WA)  --  Authorities are still investigating a deadly shooting that left five people dead in the Mason County, Washington community of Belfair.  Officials say 51-year-old David Wayne Campbell shot himself to death after a three-hour standoff with deputies Friday.  The sheriff's office says Campbell killed 49-year-old Lana J. Carlson, 16-year-old Quinn Carlson, and 18-year-old Tory Carlson.  Officials are waiting for notification of next of kin before releasing the name of the last victim.