A Canadian farming family is confronting shock and grief after three young girls were killed after being buried alive in a truckload of canola seeds.

The girls - 13-year-old Catie Bott and her twin sisters, Dara and Jana, both aged 11 – were killed at their Alberta farm on Tuesday, according to the local media reports.

Family members and neighbours struggled to free the girls and perform life saving techniques. Two of the girls died at the scene; the third was flown to a children’s hospital where she died from her injuries on Wednesday afternoon.

“Our kids died living life on the farm, it is a family farm. We do not regret raising and involving our kids Catie, age 13, Dara, age 11, and Jana, age 11 on our farm. It was our life,” the children’s parents said in a statement.

“Thank you for all of the overwhelming support we have received from the first responders, neighbours and friends. We would ask the media to respect our privacy at this time of grief.”

Family friend and local pastor, Brian Allan, told the Calgary Sun: “This is your worst nightmare.”

He added: “They are a wonderful family and very close friends of ours.”

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Marcel Hacault, executive director of the Canadian Agricultural Safety Association, cautioned against children playing around grain, stressing that it can be more dangerous than it ever was before due to today's large collection sizes.

“Farms are getting bigger, everything is bigger, and it only takes ten seconds to get engulfed or buried by grain. You don't have near-misses anymore. You get the fatalities,” he told CBC News.