On October 14th at approximately 8:30 p.m. officers responded to a vehicle versus pedestrian collision at North 136th Street and Greenwood Avenue North.  It appears that a vehicle was travelling southbound on Greenwood Avenue North when it struck a pedestrian crossing the street westbound at North 136th Street. The pedestrian sustained a life-threatening head injury and was transported to Harborview Medical Center by Seattle Fire Department Medics.  Officers evaluated the 90-year-old female driver at the scene for any signs of impairment due to drugs and/or alcohol, and determined that she was not impaired. Traffic Collision Investigation Squad (TCIS) detectives responded to the scene and continue to actively investigate.