Emergency officials attend to the scene of a fatal car wreck north of Nanton. Four women were killed but a six-month-old baby survived the crash. MIKE DREW/SUN MEDIA

NANTON, Alta. -- Only a six-month-old baby found strapped in its car seat survived a horrific head-on crash that killed four women yesterday afternoon about 75 km south of Calgary.

Two small cars were driving in opposite directions around noon when one lost control, leading to the deadly collision, RCMP Cpl. A.J. Mand said.

A northbound car carrying three women in their early 20s came around a corner along Hwy. 2 about 2 km north of Nanton, veered into the grassy centre median and collided with a southbound vehicle that was carrying the lone female driver and the baby.

The three women in the northbound car died while the woman in the southbound car was also killed.

All four, from Calgary, were pronounced dead at the scene. Their names have not been released. The child was airlifted by STARS to Calgary for treatment.

"The baby is OK," Mand said.

"It was rushed to hospital and is doing fine. The child is OK -- it was in a car seat."

Mounties did not specify the youngster's gender.

Mand said they are looking into whether the others were wearing seatbelts at the time of the crash.

Now police are trying to determine what caused the tragic chain of events, but said speed and alcohol were not factors.

"We're not sure what caused the accident," said Mand.

"The weather was good, the road was good."

Both vehicles were extensively damaged in the crash, one nearly cut in two.

The northbound car, the top half covered by a large tarp and appearing seemingly flattened, ended up sitting wheels-up about 30 metres off the highway's southbound lanes. One car is said to be a Volkswagen Jetta, the other a Subaru.

Traffic in the area was snarled and rerouted for hours while investigators scoured the scene.

Yesterday's crash is one of several tragedies on southern Alberta highways in recent months to result in multiple fatalities. On Aug. 26, three people -- including a 17-year-old driver -- died after their minivan crossed into the path of a semi-trailer near Strathmore.

And in July, two children and three adults from the Blood Tribe near Lethbridge were killed after the pickup truck they were travelling in slammed into a backhoe.

NADIA.MOHARIB@SUNMEDIA.CA