---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-23-024429"
form_type: "8-K"
ticker: "MLM"
cik: "0000916076"
company_name: "MARTIN MARIETTA MATERIALS INC"
filed_at: "2023-05-26T23:59:59+00:00"
generated_at: "2026-06-14T13:51:23.684639+00:00"
event_type: "regulatory"
sentiment: "negative"
materiality_score: 0.15
calibrated_materiality_score: 0.15
confidence: "high"
source: SEC EDGAR
---

# Martin Marietta receives MSHA section 107(a) order at Stamper Underground Mine for lack of fall protection

## Summary
- Order issued May 23, 2023, at Stamper Underground Mine in Kansas City, Missouri.
- Maintenance personnel worked 12 feet off ground without fall protection.
- Corrective action taken, order terminated; no injuries reported.

## SEC filing metadata
- accession: 0000950170-23-024429
- form_type: 8-K
- ticker: MLM
- cik: 0000916076
- company_name: MARTIN MARIETTA MATERIALS INC
- filed_at: 2023-05-26T23:59:59+00:00
- event_type: regulatory
- sentiment: negative
- materiality_score: 0.15
- calibrated_materiality_score: 0.15
- confidence: high
- sec_items: 1.04
- EDGAR index: https://www.sec.gov/Archives/edgar/data/916076/000095017023024429/0000950170-23-024429-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/916076/000095017023024429/mlm-20230523.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-23-024429
- JSON: https://secwatch.observer/filing/0000950170-23-024429.json
- Plain text: https://secwatch.observer/filing/0000950170-23-024429.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.