A tragic crash that claimed the life of an Alberta mom and left her husband and children in hospital Sunday could have been much worse if not for the heroic efforts of strangers.

Kunthea and Richard Altvater were driving their three young children home to Coaldale when their minivan crashed off Highway 3 just west of Fernie and plunged upside down into Elk River.

Seeing the family trapped, two Good Samaritans stopped their car and jumped into the frigid water to pull all five of them out.

Kunthea and her four-year-old son had already stopped breathing. Frantic CPR efforts by Mounties and a doctor helped revive the boy but his mother was later pronounced dead at Fernie Hospital.

The Good Samaritans, a man and woman, have yet to be publicly identified.

Witnesses from the area said the highway was thick with slushy wet snow, and question why snowplows didn’t clean up the roads earlier in the day.

“It was just the shoulders of the road that had slush on it, about six inches,” said Mike Greenwood, who added that a driver plowed the area after the accident.

“It took him maybe 40 minutes. They could have done it in the morning.”

The cause of the crash has not been confirmed but Mounties believe the minivan may have been trying to pass another vehicle when the driver lost control.

Two of the Altaver children were flown to Alberta Children’s Hospital with severe injuries while the father and third child were treated at Sparwood Hospital for hypothermia and minor wounds.

Family friends are planning a fundraiser to help the young family back in Coaldale.

With a report from CTV British Columbia’s Lisa Rossington