An 18-year-old woman from The Dalles died in a single vehicle accident Sunday morning on westbound Interstate 84 west of Rowena.  According to the Oregon State Police, the vehicle driven by Aileen Pineda-Garcia was traveling west on I-84 near milepost 76 just west of the Rowena exit before 6 a.m. Sunday, and for unknown reasons left the roadway and went into a ditch, and then collided with a tree.  Pineda-Garcia, who was the sole occupant of the vehicle, was pronounced deceased at the scene.  Investigators concluded that both speed and weather were likely a contributing factor in the crash  The Oregon State Police was assisted at the scene by Mid-Columbia Fire & Rescue and ODOT.