March 20, 2003 11:00 pm

UNION — Two people were seriously injured and another sustained minor injuries Thursday evening when their vehicle rolled and skidded along Highway 237 near milepost 19.

According to Oregon State Police reports, Derrick Dean Carlton, 17, 87 Rapid Run Loop, La Grande, was driving a Ford Mustang along the highway at about 10 p.m. when he suddenly veered to the right.

He then steered hard left, trying to correct, OSP Sgt. Scott Moore said, but the car overturned. It appeared the vehicle slid about 250 feet along the edge of the highway before stopping.

With Carlton in the vehicle were passengers Billy Helton, 16, 604 Y Ave., and Leah Noel Troen, 16, 2612 Cove Ave., both of La Grande. Troopers at the scene at about 10:24 p.m. determined that none of the three were wearing seat belts or shoulder straps when the accident occurred.

Carlton and Helton were both reported by the state police as receiving "very serious injuries" after being ejected from the Mustang.

They were later transported by air to St. Alphonsus Medical Center in Boise for treatment.

Troen, who was not transported, received minor injuries and was under medical observation, authorities said.