(Cottage Grove, OR)  --  Police say a four-year-old was killed and three other people were injured in a crash in Lane County.  Authorities say a 23-year-old Eugene woman drifted off the roadway while traveling east yesterday along Cottage Grove-Loraine Highway.  The SUV went down an embankment, causing minor injuries to the mother and two children.  The four-year-old child died at the scene.  Oregon State Police say all three children were properly restrained in the vehicle.