A Toyota Camry was heading west on Highway 28 east of Wenatchee when it hit an oncoming Northwestern Stage Lines charter bus, The Seattle Times reported.
A 66-year-old Spokane man who was driving the bus was killed, along with a 17-year-old female driver and a 17-year-old male passenger in the Camry, both from East Wenatchee, the Washington State Patrol said.
A bus passenger died later at a hospital. Seven others, ages 24 to 71, were hurt in the crash and taken to local hospitals, troopers said.
The car also hit and damaged the car it was trying to pass, but no one inside that vehicle was hurt, according to the state patrol.
Jacob Price, owner of the Spokane-based bus company, said the crash happened during a scheduled route between Seattle and Spokane.
He said about 20 people were on the bus.
Price told the newspaper the crash was caused by a driver trying to pass while travelling at an "excessive speed," and the company was working with state troopers and the state transport department to learn more.
The names of those killed in the crash have not yet been released.