The horrific incident began at about 10:25 a.m. when police received a number of calls about a collision at Lake Washington Boulevard and Park Drive that also involved a pedestrian down on the pavement.
Officers and medics rushed to the scene and found a woman on the street with life-threatening injuries. Despite the efforts of medics, she died about an hour later, said Detective Robert Onishi of the Renton police.
A preliminary investigation found that a 77-year-old Issaquah man had been out on a drive in his 1995 Mercedes with his sister, a native of Germany, who was in the area for a visit and was riding as a passenger in the car.
As the car was heading west on Park Drive, it got into a minor fender-bender and the brother brought the car to a stop.
The sister then got out of the car and walked behind it to direct traffic around them. As she was standing there, the brother backed up the car and ran over his sister. He then drove forward, running over his sister again and running into the side of a passing commercial truck.
Onishi said it appears the brother ran over his sister accidentally.
"We don't know if he had some kind of condition or some kind of episode," he said. The brother was taken to the hospital for evaluation.
The sister died despite the best efforts of medics at the scene.