(Portland, OR)  --  Portland police say they've arrested a hit-and-run suspect who tried to jump off the Morrison Bridge.  Authorities say 24-year-old Robert Charles Harvey had crashed into several vehicles and hit a pedestrian in the area of Southwest 3rd Avenue and Oak Street around one a.m. yesterday.  Police say Harvey then got out of his vehicle and ran toward the bridge after taking off most of his clothes.  Officers were able to grab Harvey as he dangled off the bridge, and held onto him until they received assistance in pulling him back over the rail.  No one was seriously hurt.