(Portland, OR)  --  Police are investigating a crash that left a motorcyclist lying unconscious in Southeast Portland.  Authorities say the wreck happened around 9:30 last night at the intersection of Southeast 45th Avenue and Belmont.  The motorcyclist, described as a man in his 30s, was taken to a hospital, but there's no word on his condition.  Police say the driver of the car involved in the crash remained at the scene and cooperated with the investigation.