VIDEO: Multiple-vehicle collision in Montana after a dust storm, six people have died

 

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At least six people have been killed after a dust storm caused a pile-up of 21 vehicles in Montana.

Strong winds whipped up the dust and left drivers with “zero visibility” before the “mass casualty crash” on Friday afternoon.

Gusts of 60mph were recorded around the time of the pile-up on the Interstate 90 highway near Hardin, a city in the state’s south.

It is not clear how many were injured in the incident but a highway patrol official said extra ambulances had to be called in from another city to help.