(Portland, OR)  --  State troopers and the ATF are joining the investigation into a three-alarm fire that displaced more than two-dozen people in Wilsonville.  Firefighters responded to the blaze Sunday morning in a condominium complex under construction at Southwest Collina Lane and Paris Avenue.  Authorities evacuated about 25 people from nearby homes.  About 20 homes were damaged, and fire officials say some of the homes are a total loss.  An investigation is ongoing into what caused the fire.