(Portland, OR)  --  Authorities say a woman who was stabbed to death at the apartment complex where she worked was a wife and a mother of two.  Twenty-nine-year-old Nicole Laube [[ lob ]] was fatally stabbed Tuesday afternoon at the Timber Creek Apartments in Cedar Mill.  Washington County sheriff's deputies say they only have a vague description of the suspect, who's still at large.  Investigators say they don't know whether Laube knew her killer.