COALDALE, Alta. -- Two teenage boys are dead after the pickup truck they were in slammed broadside into a semi in southern Alberta.

Coaldale RCMP say the tractor-trailer unit flipped at least once when the pickup struck it at high speed Thursday afternoon at the intersection of two gravel roads.

The 17- and 14-year-old boys, both from the Taber area, died at the scene.

A 25-year-old man who was driving the semi was taken to the Lethbridge hospital for treatment of non-life-threatening injuries.

Police say it was clear and sunny at the time of the crash.

They also say the north and south sides of the intersection have yield signs.