ENUMCLAW, Wash. -- One person was killed on Tuesday in a collision involving a Metro bus and two passenger vehicles near Enumclaw.

VIDEO: Metro Bus Involved In Fatal Collision

A Toyota 4Runner was eastbound on state Route 164 in front of the bus at 4:30 p.m. and slowed to turn left into a business, the Washington State Patrol reported.

The bus, driven by 35-year-old Sandie Olosky of Issaquah, swerved to the left, struck the left rear of the 4Runner and continued into the westbound lane, where it collided head-on with a Toyota pickup, the patrol said in a news release.

VIDEO: Friends And Family Of Crash Victim Want Answers

According to the Amalgamated Transit Union, Olosky had previously been terminated in 2005 for alleged gross misconduct, but following an arbitration hearing in November 2005 she was reinstated.

Her union shop steward told KIRO 7 Eyewitness News reporter Gary Horcher that her firing had nothing to do with accidents or traffic infractions, but he said he couldn't say what the accusations were. He said she was "re-hired for a reason."

"The 4Runner driver said that he actually saw the bus coming up behind him at a high rate of speed to the point where he actually pulled off onto the shoulder as much as he could," Trooper Cliff Pratt told KIRO 7 Eyewitness News.

The pickup driver, identified as Michael A. Dahlquist, 21, of Enumclaw, was killed instantly. His passenger, Aaron M. Stingle, 21, of Enumclaw, suffered minor injuries.

Troopers said they are trying to determine whether the bus driver is at fault for attempting to pass.

"It's a legal passing zone is this area, but obviously we do have to worry about due care and caution when you pass. You have to make sure nobody's coming in the opposite direction," Pratt said.

The bus driver and three passengers on the bus were not hurt.

The bus was on route 915, which runs between Auburn and Enumclaw.