In a heartbreaking twist to a tragic story, it has been confirmed that the Saskatchewan woman killed by a school bus Monday had two children aboard the bus when the crash happened.

Monica Domes, 40, of the Biggar district, died when the bus struck a pickup truck and cattle trailer that were parked on the side of a highway.

Three children and the bus driver were injured.

"It's just a very shocking thing to have happened," close family friend Sharon Gamble told CBC News. "We definitely uphold the family in prayer because that is about the only thing that is sustaining right now."

The RCMP have confirmed that two of the three children on board the bus were related to Domes.

Gamble said Monica Domes was a good mother to her twin, eight-year-old boys, who were released from hospital after being treated for minor cuts and bruises after the crash.

The bus driver remains in hospital in Saskatoon.

The cause of the crash is still unknown.

"It's just unbelievable how something like that could happen when it was such a clear day," Gamble said.

RCMP continue to investigate.