A 24-year-old Oakville woman was killed Sunday night in a one-car crash in East County.

The woman was a passenger in a car driven by a 25-year-old Elma man, a release from the Washington State Patrol says. The two were northbound on Capitol Forest D Line Road, north of Oakville in the Capitol State Forest, when the vehicle failed to negotiate a curve and left the road to the right. The vehicle traveled down an embankment and struck a tree. The accident was reported around 9 p.m. Sunday.

The woman was wearing her seat belt. She died at the scene, the release states.

The driver, who was not wearing his seat belt while driving a 2013 Ford F-250 pickup, was injured and transported to Providence St. Peter Hospital in Olympia.

Alcohol or drugs were believed to be involved, officials said. The road was closed for about seven hours during the investigation, which is ongoing.