(Portland, OR)  --  An investigation is ongoing into an explosion that blasted an apartment garage in Aloha.  The Washington County Sheriff's Office says crews arrived on the scene early Wednesday morning to find the garage door severely damaged by an explosion from inside.  They cleared the area and called in the Portland Police Bureau's explosive disposal unit.  Detectives got a search warrant to remove and dispose of the hazardous materials from the garage.  Several items were saved for evidence.  No one was hurt.