{"filing":{"accession_number":"0001710366-26-000045","cik":"0001710366","ticker":"CNR","company_name":"Core Natural Resources, Inc.","form":"8-K","filing_date":"2026-05-19","report_date":null,"primary_document":"cnr-20260513.htm","primary_document_url":"https://www.sec.gov/Archives/edgar/data/1710366/000171036626000045/cnr-20260513.htm"},"events":[{"id":10247,"run_id":8987,"accession_number":"0001710366-26-000045","anchor_item_number":"1.04","event_type":"other_material","event_domain":"catchall","is_material":true,"confidence":0.65,"summary":"This disclosure reports a mine safety matter under Item 1.04 (Mine Safety – Reporting of Shutdowns and Patterns of Violations). An imminent danger order was issued on May 13, 2026 for elevated methane concentrations at the Leer South mine in West Virginia, but was terminated and vacated by MSHA on May 14–18, 2026 after further discussion. While the order was ultimately vacated, the initial issuance of an imminent danger order and the regulatory interaction are material operational events that would affect investor assessment of the registrant's mining operations and regulatory compliance. This does not fit neatly into other specific event categories (not a shutdown, not a pattern of violations, not a typical operational disclosure), so other_material is most appropriate.","company_name":"Core Natural Resources, Inc.","ticker":"CNR","filing_date":"2026-05-19","form":"8-K","submitted_at":null,"items":[{"id":374,"accession_number":"0001710366-26-000045","item_number":"1.04","item_title":"Mine Safety – Reporting of Shutdowns and Patterns of Violations.","event_type":"other_material","event_domain":"catchall","is_material":true,"confidence":0.65,"reasoning":"This disclosure reports a mine safety matter under Item 1.04 (Mine Safety – Reporting of Shutdowns and Patterns of Violations). An imminent danger order was issued on May 13, 2026 for elevated methane concentrations at the Leer South mine in West Virginia, but was terminated and vacated by MSHA on May 14–18, 2026 after further discussion. While the order was ultimately vacated, the initial issuance of an imminent danger order and the regulatory interaction are material operational events that would affect investor assessment of the registrant's mining operations and regulatory compliance. This does not fit neatly into other specific event categories (not a shutdown, not a pattern of violations, not a typical operational disclosure), so other_material is most appropriate.","classifier_version":"claude-haiku-4-5-20251001+prompt-9e0ffca5","taxonomy_version":"v1","classified_at":"2026-05-20T02:46:09.763706+00:00","company_name":"","ticker":null,"filing_date":""}]}],"classifications":[{"id":374,"accession_number":"0001710366-26-000045","item_number":"1.04","item_title":"Mine Safety – Reporting of Shutdowns and Patterns of Violations.","event_type":"other_material","event_domain":"catchall","is_material":true,"confidence":0.65,"reasoning":"This disclosure reports a mine safety matter under Item 1.04 (Mine Safety – Reporting of Shutdowns and Patterns of Violations). An imminent danger order was issued on May 13, 2026 for elevated methane concentrations at the Leer South mine in West Virginia, but was terminated and vacated by MSHA on May 14–18, 2026 after further discussion. While the order was ultimately vacated, the initial issuance of an imminent danger order and the regulatory interaction are material operational events that would affect investor assessment of the registrant's mining operations and regulatory compliance. This does not fit neatly into other specific event categories (not a shutdown, not a pattern of violations, not a typical operational disclosure), so other_material is most appropriate.","classifier_version":"claude-haiku-4-5-20251001+prompt-9e0ffca5","taxonomy_version":"v1","classified_at":"2026-05-20T02:46:09.763706+00:00","company_name":"Core Natural Resources, Inc.","ticker":"CNR","filing_date":"2026-05-19"}]}