Initially police said seven were dead, but they lowered the number to six after investigators were further able to examine the car involved in the crash.
Police were called early Saturday to the scene of what they thought was a semi rollover about six kilometres southeast of the city straddles the Saskatchewan-Alberta border.
When officers arrived, they determined a car had also been involved in the crash, said Cpl. Rob King.
"Once they arrived on scene, they determined that it wasn't a simple rollover of a semi truck as at was first initially reported, but it had been a collision between a semi tanker truck that was hauling crude oil and a four-door small passenger car," he said.
"The semi had flipped over onto its top, onto its roof, into a slough, and the four-door passenger car was completely submerged."
RCMP say the victims were all from the car — three males and three females ranging in age from 13 to 17. Police initially indicated the victms were older but pinpointed the ages late Saturday after speaking to family members.
RCMP say the collision happened at an intersection while the car had been heading east along a rural township road.
Five of the victims were pronounced dead at the scene. One was rushed to hospital but died a short time later.
"Somehow he had been able to free himself from the vehicle when our members got there," King said
Police have not released the names of any of the victims, but King said they were from the "rural area."
The driver of the semi was taken to hospital with undetermined injuries.
King said the investigation could take months to complete.
He said support would be available for the victims' families as well as the emergency responders who were at the scene.
Police closed off roads in the area while they investigated.
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