(Vancouver, WA)  --  Officials say a 17-year-old who was hit and killed by a train in Vancouver committed suicide.  The Clark County Medical Examiner's Office made the ruling yesterday on Joshua J. Develle, who died around 2:42 Monday morning of blunt-force trauma.  Vancouver police say Develle was walking on the tracks that cross Southeast 164th Avenue near Southeast Rivershore Drive when he was killed.