A Toyota van hit a car driven by a Prosser woman at 5 p.m. Sunday as both were traveling east on Interstate 82, according to the Washington State Patrol.
Mary Walker, 37, of Yakima, was driving the van when it hit a Chrysler Pacifica about five miles east of Prosser, according to police reports. She was taken to Prosser Memorial Hospital.
Miriah Martinez, 38, of Prosser, was driving the Chrysler. She was not injured.
The state patrol is blaming driver negligence for the crash. No charges are planned.