The accident happened about 20 kilometres west of Watson Lake, Yukon.

Watson Lake RCMP say a 61-year-old Alberta man was killed when his tractor trailer unit hit another truck that was broken down on the Alaska highway.

It happened around 4 a.m. Saturday morning about 20 kilometres west of Watson Lake.

The eastbound tractor trailer also hit a service truck that was parked beside the broken down truck.

Two other people were injured — a 70 year passenger in the highway truck, and a 21-year-old Manitoba man who was working on the parked truck.

Both men were taken to hospital in Watson Lake.

One was then airlifted to Vancouver and the other to Whitehorse for medical treatment.

Police do not know their current condition.

A portion of the Alaska highway was closed for about 12 hours on Saturday, while police investigated the accident.

Police say alcohol, speed and road conditions are not considered factors in the crash.

The name of the driver who was killed has not been released.