If this story is true, it is completely new to me as an ignition source for a wildland fire. Why would burning coal be on a truck?

Below is an excerpt from an article at TwinCities.com:

GRAND FORKS, N.D. — Grass fires along a roughly 60-mile stretch of Interstate 29 Wednesday could have been caused by burning pieces of coal falling from a truck’s conveyor and onto the road, according to Walsh County Sheriff Ron Jurgens.

The truck was traveling south from Walhalla, N.D., toward Grand Forks, he said.

“Every time the wind would gust, it would blow some … onto the roadway,” said Jurgens Thursday.

Jurgens said a vehicle dragging its chains “had nothing to do” with fires along I-29, as had been reported earlier.

Fires popped up all along the route the truck took, Jurgens said, from Walhalla, along North Dakota Highway 5, south down I-29, to Grand Forks.