It's a parent’s worst nightmare -- laying a child to rest.

That's the reality for the families of six teens who were killed in a tragic highway crash near Lloydminster.

A memorial service for 17-year-old Kristopher Tavener was held Tuesday afternoon in the town of Lashburn.

It’s the last in a series of services that began Friday with the burial of 15-year-old Tarren Attfield, who was laid to rest in Lashburn.

On Saturday, more than 1,000 people attended a service for 14-year-old McKenzie Moan, 13-year-old Naomi Salas-Schafer and 14-year-old Aimie Hurley in Lloydminster.

A service for 16-year-old Jayden Boettcher was also held Saturday in the town of Marshall.

The six teens were travelling in a small two-door car when they collided with a tanker truck carrying crude oil on a rural road on July 27.

The crash took place shortly after 4 a.m., about six kilometres south of Lloydminster, which straddles the Alberta and Saskatchewan border.

When police arrived to scene, the tanker truck was on its roof and the car was completely submerged in a nearby slough, hidden out of sight.

Police said the driver of the truck was trapped inside the vehicle for about an hour before he was freed and rushed to hospital.

Five of the teens were pronounced dead at the scene, while one was rushed to hospital, where he was pronounced dead.

Saskatchewan RCMP have said it will take at least three months to complete an investigation into the fatal crash.

Police have yet to determine who was driving the car at the time of the accident and whether that teen had a driver’s license.

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

With files from CTVNews.ca Staff