Two women were killed and four other people were injured on a Montana highway after dense smoke from a fire billowed across it.
The women, aged 17 and 20, were killed when their Pontiac Grand Prix was one of four vehicles in solved in the accident on Interstate 15.
Officials say that a tractor-trailer slowed because of the smoke from a controlled burn near the road, causing the fatal pile-up.
The women, who have not been identified, were in the third car in the crash and were pronounced dead at the scene.
Investigators say it is unclear if the women were wearing seatbelts at the time of the accident near Conrad, Montana.
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The driver of the truck was a 57-year-old man from Alberta, Canada, who told officials he had to slow down to 25mph because of poor visibility caused by the smoke.
The road is surrounded on both sides by agricultural land and it is likely that the fire was part of a controlled agricultural or debris burning, according to wildfiretoday.com.
