(Gresham, OR)  --  Police are investigating a crash that critically injured a pedestrian while he was on a sidewalk in Gresham.  Authorities say the 36-year-old man was standing on the southwest corner of East Burnside and Southeast 172nd Avenue when he was hit by an SUV yesterday evening.  The man was rushed to a hospital, where he's listed in critical condition.  Police say the Portland man who drove the SUV cooperated with officers.