01/14/2012 02:59 EST | Updated 03/15/2012 05:12 EDT

Mom of twins dies in Manitoba highway crash

A 32-year-old woman from Minnedosa, Man. died when her minivan crashed with a semi-trailer truck on the Trans-Canada Highway near Brandon. The woman's four-year-old twins survived the crash and are in hospital in Winnipeg.

RCMP said the driver of the truck was not hurt.

The crash happened around 5:20 p.m. CT, Friday.

According to police, the force of the impact sent the minivan into a field north of the highway. RCMP said their preliminary investigation suggests the collision took place as the minivan was entering the westbound lanes of the Trans-Canada from a rural road that intersected with the highway.

Police said the woman was killed instantly.

Initially the four-year-old twins were treated in hospital in Brandon.

However the girl was flown to Winnipeg Friday night in critical condition. She has since improved to stable condition.

Her twin brother was in stable condition in Brandon and has also been transferred to Winnipeg for further treatment.

No names were released.

The driver of the semi was a 64-year-old man from North Dakota.

Officers from the Blue Hills detachment of the RCMP were continuing to investigate with help from traffic analysts and a specialized crash investigation team.

Traffic on the Trans-Canada Highway was slow around the area of the crash until about 10 p.m. Friday.