SUMNER, Wash. -- Four people were injured in a crash near here Tuesday afternoon and the driver who caused the crash has been arrested for investigation of vehicular assault, the Washington State Patrol said.

Trooper Brandy Kessler said the crash happened just after 12:30 when the driver of a Dodge Stratus crossed the center line and collided head-on with a Volkswagen Passat in the 10800 block of State Route 162.

The 70-year-old woman driving the Passat, and a 22-year-old passenger in the Stratus, suffered injuries severe enough to warrant being flown by medical helicopter to Harborview Medical Center in Seattle. They were listed in serious condition Tuesday evening.

The driver of the Stratus, identified by the Patrol as 22-year-old Jacqueline P. Weston, of Federal Way, and a passenger in the Passat were taken to Good Samaritan Hospital in Puyallup with serious injuries.

Investigators determined that Jacqueline Weston was driving with a suspended license and she was arrested for investigation of three counts of vehicular assault.

Kessler also said drugs also played a role in the crash.