# NTSB Safety Recommendation P-74-048

**Citation:** P-74-048  
**Type / status:** guidance / guidance  
**Agency:** National Transportation Safety Board  
**Effective:** 1974-10-24  
**Published:** 1974-10-24

THE NTSB RECOMMENDS THAT THE WASHINGTON GAS LIGHT COMPANY: CONTINUE ITS EFFORTS AT THE ACCIDENT SITE TO DISSIPATE THE RESIDUAL GAS REMAINING IN THE GROUND.

## Document text

NTSB safety recommendation P-74-048.

THE NTSB RECOMMENDS THAT THE WASHINGTON GAS LIGHT COMPANY: CONTINUE ITS EFFORTS AT THE ACCIDENT SITE TO DISSIPATE THE RESIDUAL GAS REMAINING IN THE GROUND.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1974-10-24

Adopted Date: 1974-10-24

Overall Date Closed: 1976-09-10

Synopsis: ON JUNE 23, 1973, A SERIES OF EXPLOSIONS, FOLLOWED BY FIRE, OCCURRED AT 12321 WELLING LANE IN BOWIE, MARYLAND. THREE OCCUPANTS OF THE HOUSE WERE KILLED, AND A FOURTH WAS INJURED; THE HOUSE WAS BADLY DAMAGED. HOUSES IN A FIVE-BLOCK AREA WERE EVACUATED.

Ntsbnumber: PLD73XR006

Report Number: PAR-74-05

Addressee Name: Washington Gas

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-09-10

Addressee Organization Type: P-Private Industry

Communication Date: 1975-01-03

Communication Type: Official Correspondence

Communication Contents: WASHINGTON GAS LIGHT COMPANY LTR: THEY HAVE COMPLIED WITH THE RECOMMENDATION. THE NUMBER OF VENT HOLES WERE INCREASED IN THE RESIDUAL GAS AREA TO PERMIT THE TRAPPED GAS TO ESCAPE. ALSO A NUMBER OF HIGH-SUCTION-TYPE BLOWERS WERE INSTALLED OVER A NUMBER OF VENT HOLES TO ACCELERATE THE REMOVAL OF THE RESIDUAL GAS.

## Provenance

- Official: Yes
- Source: <https://data.ntsb.gov/carol-main-public/sr-details/P-74-048>
- Source ID: `ntsb-pipeline`
- SHA-256: `6a69ce9dae24b734531311cbc49ec321b88afcd5b41a0f58b4f07c1d0cd46b13`
- Retrieved: 2026-08-20T04:57:24.741Z
- Exported: 2026-08-26T19:38:06.305Z
- Document slug: `ntsb-recommendation-p-74-048`

### Source metadata

```json
{
  "recordKind": "ntsb_safety_recommendation",
  "safetyRecommendationNumber": "P-74-048",
  "recommendationMode": "Pipeline",
  "topicMode": "Pipeline",
  "ntsbNumber": "PLD73XR006",
  "priority": "CLASS II",
  "overallStatus": "Closed - Acceptable Action",
  "overallStatusAcronym": "CAA",
  "overallDateClosed": "1976-09-10",
  "lastModifiedDate": "2016-11-15",
  "reportNumber": "PAR-74-05",
  "reportUrl": "https://www.ntsb.gov/investigations/Pages/PLD73XR006.aspx",
  "transmittalLetterUrl": "http://www.ntsb.gov/safety/safety-recs/recletters/P74_37_49.pdf",
  "addressees": [
    {
      "addresseeName": "Washington Gas",
      "addresseeStatusAcronym": "CNLA",
      "addresseeStatus": "Closed--No Longer Applicable",
      "addresseeDateClosed": "1976-09-10",
      "addresseeDetails": [
        {
          "addresseeAcronym": null,
          "addresseeOrganizationType": "P-Private Industry",
          "isFromNtsb": false,
          "communicationDate": "1975-01-03",
          "communicationType": "Official Correspondence",
          "communicationContents": "WASHINGTON GAS LIGHT COMPANY LTR: THEY HAVE COMPLIED WITH THE RECOMMENDATION. THE NUMBER OF VENT HOLES WERE INCREASED IN THE RESIDUAL GAS AREA TO PERMIT THE TRAPPED GAS TO ESCAPE. ALSO A NUMBER OF HIGH-SUCTION-TYPE BLOWERS WERE INSTALLED OVER A NUMBER OF VENT HOLES TO ACCELERATE THE REMOVAL OF THE RESIDUAL GAS."
        }
      ]
    }
  ],
  "jurisdiction": "US"
}
```