Knox Bridge Highway has reopened after a car accident that injured a 2-month-old boy and killed his parents.

Cherokee County Fire and Emergency Services spokesman Tim Cavender said authorities responded to a two-vehicle accident this afternoon on Knox Bridge, just west of Fields Landing Drive.

"Cherokee County firefighters arrived on the scene to find a head-on collision between a gold Ford Focus automobile and a red Dodge pick-up truck," he said in a statement. "The 48-year-old male driver of the Focus and a 39-year-old passenger died at the scene."

The baby, who was in the rear of the automobile, was transported to Children's Healthcare of Atlanta at Scottish Rite with a right broken leg and a "traumatic" brain injury.

Also injured were the driver of the pickup truck and her passenger.

The driver had possible fractures to her lower extremities and her passenger complained of neck and back pain. Both women were transported to WellStar Kennestone Hospital in Marietta.

Authorities have not determined what caused the accident, which remains under investigation.

"According to evidence at the scene and eye witness accounts, the Ford Focus, which was traveling eastbound, crossed the center line and struck a Dodge pick-up truck which was traveling westbound," Lt. Jay Baker, spokesman for the Cherokee County Sheriff's Office, said. "Currently investigators with the Cherokee Sheriff’s Office Traffic Enforcement Unit are attempting to determine what caused the driver of the Focus to cross the center line."

Pending notification of relatives, Baker said the Sheriff's Office will not release the names of the boy or his parents.