A grandmother and her 2-year-old granddaughter were killed in a crash on Interstate 15 early Saturday morning after a DUI suspect plowed into their family vehicle.
California Highway Patrol (CHP) officials said the deadly crash happened around 1:45 a.m. on southbound I-15 at Scripps Poway Parkway, near Mercy Road.
A family – including a 64-year-old grandma, a toddler, a 5-year-old girl and the 35-year-old mother of the children – were in a Honda when a silver Cadillac CTS crashed into them.
The driver of the Cadillac -- now identified by officials as Grant Stewart Thoren, 31 -- stopped momentarily on the right shoulder of the freeway, but then fled the scene.
CHP officials said that due to the damage from the hit-and-run collision, the Honda became disabled in the traffic lanes.
Moments later, a man driving a red pickup truck, accompanied by a passenger, failed to see the disabled Honda and slammed into the vehicle. That drive remained at the scene.
When emergency crews arrived, the Honda was so mangled they had to extricate the family from inside.
The grandmother and 2-year-old girl did not survive, CHP said.
The 35-year-old woman the 5-year-old girl were rushed to local hospitals with major injuries. The girl suffered a concussion and is currently being treated at Rady Children's Hospital, while her mother is hospitalized at Sharp Memorial.
The passenger in the red pickup truck was also taken to a local hospital with unspecified minor injuries. Officials said the driver of the truck was not injured.
Investigators shut down several lanes along the freeway following the deadly hit-and-run. They also launched a search for the driver of the Cadillac who fled the scene.
By 7:15 a.m., CHP officials confirmed Thoren had been arrested at his home in Vista on suspicion of driving under the influence.
Thoren is facing several charges including DUI, felony hit-and-run and homicide, the CHP confirmed.
Investigators said Thoren told them that after the crash, he exited the freeway on Mira Mesa Boulevard, drove to a gas station, called a towing company and had his car towed to his home in Vista.
CHP officials said the driver of the tow truck did not know Thoren had been involved in the deadly hit-and-run when he towed him to Vista. The tow truck driver later heard the story on the news, and then called CHP to report that he had driven the suspect home.
NBC 7 reached out to the towing company where the driver works, but they declined an interview Saturday morning.
The investigation is ongoing.
On Saturday morning, Thoren's Cadillac remained in the driveway of the home in Vista. Investigators collected evidence from the vehicle.
CHP officials said it appears the home where the DUI suspect lives may be some type of "sober living" home.
Investigators said the driver of the red pickup truck involved in the second collision with the family's Honda was not driving under the influence.
Well into Saturday, all lanes, except for the carpool lane, along southbound I-15 near the crash site remained closed to traffic.
A SigAlert was issued in the area, and traffic was backed up for miles, with single-digit speeds from Carmel Mountain Road. Motorists were advised to use State Route 56 as an alternate route to get around the area but traffic on that freeway was also sluggish. CHP expected to have all lanes cleared by the afternoon.
At 12:40 p.m., Caltrans said all lanes on southbound I-15 had re-opened to traffic. Get traffic updates here.
The names of the grandmother and toddler killed in the hit-and-run DUI crash have not yet been released. Investigators said the mother and children are from Temecula, just north of San Diego County, while the grandmother was from Fairfield, California.