# NTSB Safety Recommendation P-73-040

**Citation:** P-73-040  
**Type / status:** guidance / guidance  
**Agency:** National Transportation Safety Board  
**Effective:** 1973-08-24  
**Published:** 1973-08-24

THE NTSB RECOMMENDS THAT THE OFFICE OF PIPELINE SAFETY OF THE DEPARTMENT OF TRANSPORTATION: GIVE ADDITIONAL REGULATORY CONSIDERATION TO THE EFFECTS OF GRAPHITIZATION ON THE RESISTANCE OF CAST-IRON MAINS TO EXTERNAL LOADS. LOCALIZED AND GENERAL GRAPHITIZATION SHOULD BE DEFINED.

## Document text

NTSB safety recommendation P-73-040.

THE NTSB RECOMMENDS THAT THE OFFICE OF PIPELINE SAFETY OF THE DEPARTMENT OF TRANSPORTATION: GIVE ADDITIONAL REGULATORY CONSIDERATION TO THE EFFECTS OF GRAPHITIZATION ON THE RESISTANCE OF CAST-IRON MAINS TO EXTERNAL LOADS. LOCALIZED AND GENERAL GRAPHITIZATION SHOULD BE DEFINED.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1973-08-24

Adopted Date: 1973-08-16

Overall Date Closed: 1976-07-20

Synopsis: A GAS EXPLOSION OCCURRED ON AUGUST 31, 1972 IN THE ANNEX BUILDING OF AN ATLANTA, GA., HIGH SCHOOL. GAS HAD LEAKED INTO THE BUILDING FROM A CRACKED CAST-IRON MAIN LOCATED BENEATH THE STREET IN FRONT OF THE ANNEX. ATLANTA GAS LIGHT COMPANY (AGL) PERSONNEL ARRIVED AT THE LEAK SITE APPROXIMATELY 1 HOUR AFTER AGL WAS FIRST NOTIFIED OF THE LEAK AND APPROXIMATELY 1/2 HOUR BEFORE THE EXPLOSION. ONE PERSON DIED AND SEVEN OTHERS WERE INJURED AS A RESULT OF THE ACCIDENT.

Ntsbnumber: PLD72XR005

Report Number: PAR-73-03

Addressee Name: RSPA

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1976-07-20

## Provenance

- Official: Yes
- Source: <https://data.ntsb.gov/carol-main-public/sr-details/P-73-040>
- Source ID: `ntsb-pipeline`
- SHA-256: `2edbf90dee35f42b3e4087977fd3018c07627be225b838f6eb4840f306c88f3b`
- Retrieved: 2026-08-20T04:57:24.741Z
- Exported: 2026-08-23T09:38:55.180Z
- Document slug: `ntsb-recommendation-p-73-040`

### Source metadata

```json
{
  "recordKind": "ntsb_safety_recommendation",
  "safetyRecommendationNumber": "P-73-040",
  "recommendationMode": "Pipeline",
  "topicMode": "Pipeline",
  "ntsbNumber": "PLD72XR005",
  "priority": "CLASS II",
  "overallStatus": "Closed - Acceptable Action",
  "overallStatusAcronym": "CAA",
  "overallDateClosed": "1976-07-20",
  "lastModifiedDate": "2016-11-15",
  "reportNumber": "PAR-73-03",
  "reportUrl": "https://www.ntsb.gov/investigations/Pages/PLD72XR005.aspx",
  "transmittalLetterUrl": "http://www.ntsb.gov/safety/safety-recs/recletters/P73_37_46.pdf",
  "addressees": [
    {
      "addresseeName": "RSPA",
      "addresseeStatusAcronym": "CAA",
      "addresseeStatus": "Closed - Acceptable Action",
      "addresseeDateClosed": "1976-07-20",
      "addresseeDetails": []
    }
  ],
  "jurisdiction": "US"
}
```