(Clackamas County, OR)  --  Police are investigating after a 60-year-old man was run over and killed by a TriMet bus in Clackamas County.  Authorities say the man died shortly before six o'clock last night at the intersection of 82nd Avenue and Causey Avenue.  Witnesses told Oregon State Police that the man approached the bus with his bicycle at a bus stop.  He then reportedly began hitting the side of the bus, and when it pulled away, the man fell and was run over.