And this situation was created in the first place - how?
United Mine Workers had the major coal producers by the throat decades ago, promising total shutdown if their sometimes excessive demands were not met. At that time, America was still heavily dependent on coal in every form for its industrial base, and it was “in the national interest” for the labor unrest to be settled for the foreseeable future. Thus the settlements highly favorable to the union leadership (and not particularly favorable to the industry), but the coal producers could pass their higher costs to the consumer directly, without question, as there was no substitute for coal at the time. With the growing utilization of natural gas and the advent of atomic-powered generation stations, and the building of the national grid, dependence on coal lessened over time, but the coal producers were still saddled with these legacy costs. The natural response was to close the mining operations, and bankruptcies followed.
Every professor of economics KNOWS this progression, but whether they teach it or not, is another question.
As a past trader and investor in those companies, it was important to understand where the stock values were headed and why.