PHOENIX — The state Forestry Division on Thursday challenged the findings of liability and $559,000 in fines by state safety officials in the deaths of the 19 Granite Mountain Hotshots.

Assistant Attorney General Paul Katz, in a letter to the state Industrial Commission, called the findings of fault “contrary to law.’’ Katz, who also represents state Forester Scott Hunt, said the unanimous decision by the board was “arbitrary and capricious.’’

The letter sets the stage for what is likely to wind up in court.

The issue for the state is not so much the fine. Instead, it is the possibility that the finding of liability — including one charge that said the Forestry Division made a “willful” violation of safety standards in fighting the Yarnell Hill Fire — could become a crucial piece of evidence as the state battles the lawsuits expected to be filed.

Several family members already have filed claims, the first step in the process.

Fire Division spokeswoman Carrie Dennett would not comment, other than to say that the appeal will afford her agency “its first opportunity to present additional information to the Industrial Commission Hearing Division.’’

Earlier this month the commission, accepting the recommendations of its Division of Occupational Safety and Health, found the Forestry Division guilty of three violations.

All three are considered “serious’’ in the parlance of the agency and meriting fines.

But the agency also concluded one was “willful,’’ which has not only connotations of something beyond simple negligence but also triggers much larger fines. It also allowed the Industrial Commission to separately order the state to pay $25,000 to the survivors of each of the 19 hotshots.

Marshall Krotenberg, the lead investigator of ADOSH, said that finding was based on his conclusion that the Forestry Division, in deciding how to battle the blaze, had its priorities wrong.

“Folks were put in positions, overly hazardous positions, to protect property that was unprotectable under the current conditions of the extreme fuel, dryness, the drought and wind conditions,’’ he told the commissioners.

That, said Krotenberg, was a “willful’’ violation of worker safety laws and regulations, which merited a penalty of $70,000, plus that $25,000-per-family fine.

Krotenberg stressed that a finding of a “willful’’ violation under state law does not mean the agency or anyone working there intended to harm the hotshots or even that they acted with malicious intent.

But he said it does mean his inspectors concluded that the Forestry Division knew what it was required to do under Arizona law to protect its employees, knew it was not in compliance, and that the agency “intentionally disregarded the requirement or acted with plain indifference to the safety of their employees.’’

It is the wording of that finding that could give ammunition to survivors who are claiming millions of dollars in damages.

Commission members found two separate violations of worker safety rules they determined were serious.

One results from a finding that, when the fire broke out, the Forestry Division had not filled two positions ADOSH determined were important: the safety officer and the planning section chief.

Krotenberg said this is critical since the role of the safety officer in particular is to pay primary attention to the safety of those fighting the fire.

The other serious violation stems from the conclusion that the Forestry Division had no real plan to fight the fire, especially after the initial efforts at suppression failed.

Krotenberg said those two failures were pointed up in the fact that one reason the firefighters may have died is that the wind direction had sharply changed because of an approaching thunderstorm. But he said that would not have happened had there been proper planning of what to do in case of a storm, something that was likely given the time of the year.

“A storm was anticipated, was forecasted, everybody knew it,’’ Krotenberg said, with storm clouds on the horizon.

“There was no plan to move folks out of the way of anticipated southerly wind flows until it occurred, until it was already too late,’’ Krotenberg continued. “It became an emergency because of bad planning.’’