A woman and her 3-year-old daughter were killed Sunday night when the car they were riding in struck a utility pole near the West Main exit of I-15 in American Fork.

Killed were:Shelly Stone, 28, Sunset, Davis County.

Amber Stone, 3, Sunset, Davis County.

Utah Highway Patrol Trooper Daniel Witney said fatigue appeared to be a factor in the 6:42 p.m. crash.

Shelly Stone was driving the car and apparently overshot the exit. She then over corrected, causing the car to slide sideways, hitting the pole on the driver's side of the car.

Craig Stone, 28, is listed in serious condition at American Fork Hospital. Sons Devin, 4, and Brandon, 8 months, were treated for minor cuts and bruises.