OAKLEY (BCN) — A motorist who struck two teenage girls — killing one — in Oakley Tuesday was arrested after the incident on suspicion of driving under the influence, police said on Friday.

Kristina Salvitti, 50, allegedly exhibited signs of being under the influence after a collision at about 2:45 p.m. on East Cypress Road in the vicinity of Bethel Island Road, police Lt. Eric Navarro said.

Salvitti was the driver of a station wagon that struck two pedestrians, leaving both critically injured, Navarro said.

A 15-year-old identified as Roshel Madlangbayan succumbed to her injuries at the scene. The other girl was flown to a hospital in Oakland for treatment.

Navarro said the girls were walking along the shoulder of a rural road that has no sidewalks. It’s often used by pedestrians but is not considered a safe route for walking, he added.

The girls were all the way on the road’s shoulder and were only hit because Salvitti allegedly swerved right in her station wagon for a still undetermined reason, Navarro said.

The station wagon then went over a curb and traveled through a field before coming to rest roughly 150 yards away, Navarro said.

During initial contact with Salvitti, officers suspected that she was possibly intoxicated, Navarro said. She was also driving with an expired driver’s license.

Although police arrested the woman, investigators and the Contra Costa County District Attorney’s Office are awaiting the results of toxicology tests, which could take more than two weeks.

No formal charges have been filed against the woman as of Friday, according to the district attorney’s office.

Salvitti, who Navarro said was living out of the station wagon involved in the collision, was booked into the Martinez Detention Facility but is no longer being held there, according to the jail’s record system.