(Portland, OR)  --  Investigators are trying to determine what has caused a ten-story building in downtown Portland to appear as if it's started to buckle.  Engineers inspected the building, located at 14-hundred Southwest 5th Avenue, and determined it's structurally sound.  Meanwhile, the building was evacuated yesterday after cracks were discovered in the facade on the lower half of the structure.  KGW-TV reports the building owner will hire an engineer to conduct an evaluation and submit the findings to the city.