(Rainier, OR)  --  Columbia County authorities say a student who was expelled Monday from Rainier High School brought a gun to the campus the following day.  Deputies say an investigation revealed the 15-year-old boy took his father's gun from the family's home and brought it to the school Tuesday.  The sheriff's office says there's no indication that threats were made toward people at the school.  The teen was taken to a juvenile detention center in Cowlitz County, Washington.