(Portland, OR)  --  A man is being treated for potentially life-threatening injuries, following a crash on I-84 in Portland.  Police say the man, who was westbound on the highway yesterday morning, struck an abandoned car near 122nd Avenue, causing his vehicle to overturn.  A third vehicle was damaged in the crash, but there were no other injuries.  The 29-year-old man was taken to a hospital in critical condition.