A highway crash involving a pickup truck, a cattle trailer and a school bus Monday left one woman dead and sent three children and their bus driver to hospital. 

On Tuesday, police identified the woman who died as Monica Domes, 40, of the Biggar area.

The RCMP have confirmed that two boys on the school bus were related to Domes. 

The crash happened on Highway 4 about 25 kilometres north of Biggar, Sask., just before 4 p.m. CST on Monday. 

Police said the pickup truck, with a cattle trailer in tow, had experienced a mechanical issue and was parked on the shoulder of the highway. 

The woman later identified as Domes, who had been a passenger in the truck, was walking around the vehicle when the collision happened, RCMP say. 

She was rushed to the hospital in Biggar, but she died from her injuries. 

It's not clear what led the northbound school bus to crash with the pickup. 

"That is what is being investigated through the use of the collision analyst," said Sgt. Craig Cleary in an email. "At this point it is too difficult to tell how things happened exactly."

The bus driver and three children on board were taken to hospital as a precaution. The three children were treated for minor cuts and bruises and were released. released while the driver remains in hospital. 

The extent of his injuries wasn't immediately available. 

A man who was inside the pickup truck was uninjured. 

Highway 4 was closed at the scene for hours while RCMP tried to piece together what happened.

Biggar-area crash

A woman was killed and several others were injured in this crash involving a pickup truck, a cattle trailer and a school bus. (RCMP)

Crash at Biggar, Sask. skpic

Another view of the crash near Biggar, Sask. (RCMP)