# NTSB Safety Recommendation P-76-029

**Citation:** P-76-029  
**Type / status:** guidance / guidance  
**Agency:** National Transportation Safety Board  
**Effective:** 1976-06-23  
**Published:** 1976-06-23

PROHIBIT ANY VALVE OR PIPING CHANGES, EXCEPT UNDER EMERGENCY CONDITIONS, WHILE CONSTRUCTION IS BEING CONDUCTED WITHIN THE AREA. (URGENT)

## Document text

NTSB safety recommendation P-76-029.

PROHIBIT ANY VALVE OR PIPING CHANGES, EXCEPT UNDER EMERGENCY CONDITIONS, WHILE CONSTRUCTION IS BEING CONDUCTED WITHIN THE AREA. (URGENT)

Priority: CLASS I

Overall Status: Closed - Acceptable Action

Issued Date: 1976-06-23

Adopted Date: 1976-06-04

Overall Date Closed: 1977-07-29

Synopsis: ON JANUARY 7, 1976, EMPLOYEES AT THE MICHIGAN-WISCONSIN PIPE LINE COMPANY'S CEDARDALE, OKLAHOMA, COMPRESSOR STATION WERE DIRECTED TO OPEN A VALVE ON A SHUT-IN 12-INCH GAS-GATHERING PIPELINE IN AN ATTEMPT TO INCREASE THE FLOW INTO THE MAIN LINE. NATURAL GAS AND NATURAL GAS LIQUIDS AT 700-PSIG PRESSURE ROARED THROUGH THE VALVE, OUT THROUGH THE END OF AN OPEN 12-INCH PIPE, AND INTO A DITCH, WHERE SEVEN MEN WERE WORKING NEAR AN OPEN FLAME HEATER. THE NATURAL GAS LIQUIDS SATURATED THEIR CLOTHING AND THE HEATER SET THEM ON FIRE. FIVE MEN WERE KILLED AND TWO MEN WERE BURNED SERIOUSLY AS A RESULT OF THIS ACCIDENT.

Ntsbnumber: DCA76FP012

Report Number: None

Addressee Name: ANR Pipeline (formerly Michigan-Wisconsin Pipeline Company)

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1977-07-29

Addressee Acronym: ANR

Addressee Organization Type: P-Private Industry

Communication Date: 1976-08-10

Communication Type: Official Correspondence

Communication Contents: LTR FROM MICHIGAN-WISCONSIN PIPE LINE COMPANY: MICHIGAN WISCONSIN WILL PROHIBIT VALVE OR PIPING CHANGES WHILE CONSTRUCTION IS BEING CONDUCTED WITHIN THE AREA EXCEPT FOR THOSE NECESSARY TO MAINTAIN SERVICE AND THOSE NECESSARY TO COPE WITH EMERGENCY CONDITIONS.

## Provenance

- Official: Yes
- Source: <https://data.ntsb.gov/carol-main-public/sr-details/P-76-029>
- Source ID: `ntsb-pipeline`
- SHA-256: `4aa66ca4ce833fc8dfec4f6f4013dbd71fec67a3822c4193ebce9386fafa2052`
- Retrieved: 2026-08-20T04:57:24.741Z
- Exported: 2026-08-23T11:19:33.432Z
- Document slug: `ntsb-recommendation-p-76-029`

### Source metadata

```json
{
  "recordKind": "ntsb_safety_recommendation",
  "safetyRecommendationNumber": "P-76-029",
  "recommendationMode": "Pipeline",
  "topicMode": "Pipeline",
  "ntsbNumber": "DCA76FP012",
  "priority": "CLASS I",
  "overallStatus": "Closed - Acceptable Action",
  "overallStatusAcronym": "CAA",
  "overallDateClosed": "1977-07-29",
  "lastModifiedDate": "2017-09-06",
  "reportNumber": "None",
  "reportUrl": null,
  "transmittalLetterUrl": "http://www.ntsb.gov/safety/safety-recs/recletters/P76_27_29.pdf",
  "addressees": [
    {
      "addresseeName": "ANR Pipeline (formerly Michigan-Wisconsin Pipeline Company)",
      "addresseeStatusAcronym": "CNLA",
      "addresseeStatus": "Closed--No Longer Applicable",
      "addresseeDateClosed": "1977-07-29",
      "addresseeDetails": [
        {
          "addresseeAcronym": "ANR",
          "addresseeOrganizationType": "P-Private Industry",
          "isFromNtsb": false,
          "communicationDate": "1976-08-10",
          "communicationType": "Official Correspondence",
          "communicationContents": "LTR FROM MICHIGAN-WISCONSIN PIPE LINE COMPANY: MICHIGAN WISCONSIN WILL PROHIBIT VALVE OR PIPING CHANGES WHILE CONSTRUCTION IS BEING CONDUCTED WITHIN THE AREA EXCEPT FOR THOSE NECESSARY TO MAINTAIN SERVICE AND THOSE NECESSARY TO COPE WITH EMERGENCY CONDITIONS."
        }
      ]
    }
  ],
  "jurisdiction": "US"
}
```