LLOYDMINSTER, Sask. -- Saskatchewan RCMP believe it will take at least three months before an investigation is complete into the deaths of six teens in a car crash.

Cpl. Rob King said Monday that investigators are talking with witnesses and friends who saw the teens before they packed into a two-door car and headed out on a rural road early Saturday.

The car collided with a semi truck at an intersection south of Lloydminster, a city on the Alberta-Saskatchewan boundary. Both vehicles slammed into a nearby slough. The truck rolled onto its roof and the car sank to the bottom.

The victims -- three girls and three boys -- were between 13 and 17.

Investigators have briefly talked with the truck driver, the only one who survived the crash, said King.

But they still have a lot of work to do to piece together what happened, he said. That includes trying to determine which teen was driving the car or if that teen had a driver's licence.

"The autopsies might hopefully give us some answers about that. The reconstructionist report might shed some light."

Toxicology tests have also been ordered to determine if the teens had been drinking.

In the end, said King, the evidence may not yield all the answers.

"We want to try to get as 100 per cent positive as possible but we might never get there."

Some of the investigators are describing the crash as the worst they've ever seen, he added.

"It's a bad scene when you have six dead bodies, and six young dead bodies."

The victims have been identified as Tarren Attfield, 15, of Lashburn, Sask; Jayden Boettcher, 16, and Kristopher Tavener, 17, both of Marshall, Sask; and Naomi Salas-Schafer, 13, Aimie Candace Elizabeth Hurley, 14, and Mackenzie Moen, 14, of Lloydminster.

Autopsies are being done in Saskatoon.

The province's chief coroner, Kent Stewart, said it's going to take some time to examine the bodies. "Certainly we will do everything we can to try and accommodate families and get through this."

He said he will wait to see the results of the final police report before deciding whether to call an inquest.

"There's always lots to be learned from these types of very tragic situations," Stewart said. "How we do that is largely dependent on the outcome of the investigation."