(Portland, OR)  --  Nearly half a dozen people are injured following a shooting at an all-ages warehouse party in southeast Portland.  Police say at least five people were hospitalized following the shooting early yesterday morning at the Audio Cinema Building on Southeast Madison Street near 2nd Avenue.  A witness tells KATU-2 he saw two men arguing outside the building before one of them fired two shots into a crowd of about 300 people inside.  At least five more shots were then heard from inside the building.  It's not yet clear what led to the shooting.  All five victims are expected to survive.