A Calgary family is in mourning after a head-on highway collision in Texas on Saturday left three members dead and sent three others to hospital with serious injuries.

Police say six people were travelling south in a Honda Odyssey on Highway 1061 — about 37 kilometres northwest of Amarillo, Texas — just before 7 a.m. when it slammed head-on into a northbound tractor-trailer.

Nirmal Kaur Minhas, 68, was pronounced dead at the scene. Upinderjit Minhas, 38, and his son Meharpratap Singh Minhas, 6, were rushed to Northwest Texas Hospital, where they later died.

A map showing where the deadly crash involving the Calgary family happened, about 37 kilometres northwest of Amarillo, Texas. (Google Maps)

Mekekdeep Kaur Minhas, 10, was taken to Northwest Texas Hospital and later airlifted to United Medical Centre in Lubbock, where she remains in serious but stable condition.

Two other family members, an adult female and a child, were taken to Northwest Texas Hospital.

Speaking at a family gathering in Panorama Hills, where the family had been living, Satnam Minhas, a cousin of Upindarjit, said the family was en route to Houston, and only Upindarjit's wife and two daughters survived.

"One of our relatives phoned us from Toronto and we rushed to the house, and already the closest relatives were there. Everybody was crying," said Satnam.

Satnam said the family is still working out any funeral arrangements and what happens to the bodies of the victims.

"There are a lot of complications," he said.

"We are not sure if the bodies will come here, as my sister-in-law has a hip fracture and can't travel to Calgary, so we have to make arrangement there in the states for the funeral.

"When we get a date for the funeral over there, then we can decide if we will do something at the temple here. But most probably we are looking forward to giving the last rituals over there."

Dan Buesing, a spokesperson for the Texas Department of Public Safety, said the minivan may have crossed the centre line.

"The witness statement from the 18-wheeler driver, he said it looked like maybe the [Honda] driver had fallen asleep because they just came over into his lane of traffic and he had no time to make an evasive manoeuvre," he said. "They struck pretty much head-on … it's very sad."

The driver of the truck, Scott Garrett, 57, of Amarillo was taken to Northwest Texas Hospital with non-life-threatening injuries.

Buesing described the area as rural.

"It's pretty flat up there. It's just a two-lane road."