A federal judge has dismissed a lawsuit filed by trustees of a pension plan providing retirement benefits to tens of thousands of retired coal miners that sought $6.5 billion from the estate of the founder of what was the nation’s largest privately owned coal company. The lawsuit filed in 2021 by trustees of the United Mine Workers of America 1974 Pension Plan and Trust had claimed the estate of Robert Murray was on the hook for withdrawal liability incurred by subsidiaries of Murray Holdings.