Jeffrey D. Allred, Deseret Morning News
State trooper investigates head-on collision on U.S. 89 in Layton Thursday that killed two people in the car. Three children and the truck driver were injured.

LAYTON — A head-on collision claimed the lives of a Huntsville mother and son Thursday on U.S. 89 in Layton.

The crash happened about 3:30 p.m. between 2200 North and Sunset Drive when the 25-year-old driver of a northbound pickup suddenly swerved into southbound traffic and slammed into a car carrying the Huntsville family, said Layton Sgt. John Holden.

The 40-year-old woman and 11-year-old son, whose names were not released Thursday, were killed.

Two children, an 8-year-old girl and 7-year-old boy, both in critical condition, were flown by Life Flight and AirMed helicopters to Primary Children's Medical Center while a 13-year-old girl was taken by ambulance to McKay-Dee Hospital in Ogden. She was later airlifted to Primary Children's where her condition was stabilized.

The driver of the pickup, which flipped over, was conscious when he was taken by ambulance to Ogden Regional Medical Center, Holden said.

Holden said it is unknown why the pickup's driver crossed into oncoming traffic.

Police closed down U.S. 89 between Cherry Lane and state Route 193 while rescuers removed the victims from the scene. Firefighters pulled a firetruck in front of the crash scene.

By 7:45 p.m. northbound lanes had been reopened.

Thursday's crash was the second serious crash in as many days on U.S. 89.

A few miles away in Fruit Heights, a semitrailer hit two vehicles Wednesday morning after its brakes failed, said Utah Highway Patrol trooper Preston Raban.

"About 200 yards north of the light the semi driver discovered he had lost his brakes as he approached the red light," Raban said in an e-mail.

The driver began blowing the truck's horn to alert other drivers, but the semi hit the pickup that had entered the intersection. One person was seriously injured, and two other people received minor injuries, Raban said. That crash closed the highway for three hours while crews cleaned up diesel fuel that spilled for 50 yards when the semi jackknifed and tore open its fuel tanks.

The driver was cited for failure to stop at a red light and equipment violations, Raban said.