DENVER -- A family of six, including three children, were killed Sunday afternoon when their minivan was broadsided by a semitrailer near Hudson, Colo., the Colorado State Patrol said.

Eric Wynn of the CSP Patrol told 7NEWS the Oldsmobile minivan was going to a relative's house and missed the driveway on Weld County Road 49. The driver pulled over and was making a U-turn when it was broadsided by a tanker truck, he said.

"You have an 80,000-pound vehicle versus probably a 4,000-pound vehicle. That doesn't match up," Wynn said.

Troopers identified those killed as Adriana Ronquago, 26, and passengers Jose Vencomo, 33, and their three children, Gyareli Vencomo, 6,  Eddie Vencomo, 4, and Jesus Vencomo, 9 months, all of Thornton.    

Also killed was 28-year-old Jamie Arais, Ronquago's brother from Arizona.

Wynn said he was not sure if the victims were wearing seat belts or not, but one adult and one child were thrown from the minivan.

County Road 49 was closed while firefighters cleaned up what Wynn called a "horrific accident" that "would devastate any family."

The driver of the truck, Brian Wheeler, 53, of Firestone, was taken to a local hospital with non-life-threatening injuries, Wynn said.

The tanker was empty and there was no fire after the collision.

County Road 49 was closed for six hours between County Roads 8 and 22 after the 1:25 p.m. crash.