Taking away the thinned-out material is difficult, and sloppy thinning can increase the risk of fire by leaving dry branches and leaves on the forest floor.

ECONOMIST: The fires return

Assistant State Fire Marshal Kelly Kistner said investigators were starting in the least-damaged areas, hoping to determine the heat source or material that ignited the fire.

CNN: Powerful Texas blast left nearly 100-foot-wide crater

And the final version will be made from some, as yet unspecified, fire-retardant material.

ECONOMIST: Safety