A 19-year-old Calgary man is being investigated for impaired driving following a crash that killed a 54-year-old Lower Mainland resident on Saturday evening.

Police say the 19-year-old's newer-model blue Dodge pickup truck crossed the centre line of the Sea to Sky Highway at Cheakamus Lake Road, about five kilometres south of Whistler, crashing into a southbound limousine.

Police say the limousine exploded and was engulfed in flames, killing the driver and lone occupant, a 54-year-old man from the Lower Mainland. His name has not been released.

"This is a terrible tragedy that resulted in the death of an innocent driver," said RCMP Sgt. Peter Thiessen. "The family of the deceased victim has been affected for a lifetime and will never be the same."

The 19-year-old was taken to a local hospital for treatment of serious but non-life-threatening injuries.

Thiessen said the cause of the crash is still under investigation, but it's believed the 19-year-old was impaired by drugs at the time.

"Through the investigation we maintain there's evidence to support an impaired by drug investigation," he said.

Sea to Sky Highway at Cheakamus Lake Road

"We have a drug recognition expert as part of the investigative team and we will be investigating him for that possible offence."

The crash is under investigation by Whistler and Squamish RCMP, along with Lower Mainland District Traffic Services and the Integrated Collision Analysis and Reconstruction Service.

The Sea to Sky Highway, or Highway 99, was closed in both directions for about eight hours following the crash. The highway reopened at about 7:15 a.m. PT Sunday.