Core Natural Resources, Inc. 8-K

What Happened Core Natural Resources, Inc. (through subsidiary Mingo Logan Coal LLC) filed an 8-K on January 12, 2026 reporting that on January 8, 2026 the Mine Safety and Health Administration (MSHA) issued an imminent danger order under section 107(a) at the Mountaineer II mine in Logan County, West Virginia after an inspector found an accumulation of elevated methane in an isolated section. Mine personnel took prompt actions to alleviate the condition, methane levels were restored to acceptable limits, MSHA terminated the 107(a) order, and no injuries or illnesses were reported.

Key Details

• Filing: Form 8-K filed January 12, 2026 (Item 1.04 — Mine Safety reporting).
• Date of order: January 8, 2026.
• Entity and location: Mingo Logan Coal LLC (subsidiary of Core Natural Resources) at Mountaineer II mine, Logan County, WV.
• Outcome: Elevated methane was addressed, MSHA terminated the 107(a) order, and there were no reported injuries or illnesses.

Why It Matters This filing notifies investors of a safety-related regulatory action and its resolution. The company reports the condition was isolated, promptly corrected, and the order lifted, which suggests the incident did not cause reported harm or ongoing shutdowns per the disclosure. Investors should note the company is subject to mine-safety oversight and that such events can disrupt operations if they recur or escalate; in this case, the company reports the situation was resolved without injury.