A Heber couple was killed and two other people were seriously injured in a collision on U.S. Highway 40 early Saturday, police said.

A 19-year-old woman dropped off her 2-year-old son at a baby sitter's house and was driving to work in Park City with her 21-year-old fiance, said Utah Highway Patrol spokesman Jesse Valenzuela.

Their white Chevrolet Cavalier was westbound in Summit County near the Interstate 80 interchange when it started swerving on the road for an unknown reason about 6:30 a.m. The car went into a spin, crossed the median and was broadsided by an eastbound Jeep Cherokee.

The woman, who was seven months pregnant, and her fiance died at the scene. The 66-year-old driver of the Jeep and his 29-year-old son were seriously injured and taken to University Hospital by ambulance. Their injuries are not believed to be life-threatening.

Troopers do not believe drugs or alcohol were factors in the accident. The couple's names were not released.

Lindsay Whitehurst