Officers say the 15-year-old boy walked into traffic reaching for a letter that the wind blew out of his hand. He was with his two brothers at the time of the accident.
The oncoming driver didn't notice the boy until it was too late, clipping the boy. A witness in the car behind the driver said she saw the boy underneath the driver's car.
He is now being transported to a Seattle hospital as he suffers from serious head injuries.