One person has been seriously injured in a one-car rollover accident on Interstate 90 20 miles west of Ritzville.

The accident, which happened at 1:43 p.m., left two people trapped inside the vehicle, one of them with serious head injuries.

The Washington State Patrol reports the roadway is partially blocked due to the accident and MedStar has launched a helicopter to the scene to evacuate the injured person to the hospital.