NTSB Safety Recommendation P-26-005

NTSB safety recommendation P-26-005.

TO ATMOS ENERGY CORPORATION: After completing the action described in P-26-4, implement a training program to maintain employee and contractor proficiency on the updated procedures.

Priority: CLASS II

Overall Status: Open - Initial Response Received

Issued Date: 2026-03-26

Adopted Date: 2026-03-12

Synopsis: This report discusses the January 2024 natural gas-fueled explosions and fires at two separate homes in Jackson, Mississippi, which occurred 3 days apart, collectively resulting in one injury, one fatality, and three destroyed homes. Safety issues identified in this report include compression coupling leaks, insufficient leak management program, inadequate distribution integrity management program, ineffective public awareness program, and absence of natural gas detection alarms in buildings.

Probable Cause: The National Transportation Safety Board determines that the probable cause of the two explosions at two separate homes in Jackson, Mississippi, was the service-line pipes partially pulling out of the compression couplings, likely because of soil movement (shrinking and swelling), creating natural gas leaks that Atmos Energy Corporation identified and left unrepaired for at least 8 weeks, which enabled gas to migrate to the nearby homes and ignite. Contributing to Atmos Energy Corporation’s failure to prevent the accidents were the operator’s: (1) insufficient leak management program, which did not determine appropriate monitoring timelines for leaks in adverse-soil conditions; (2) ineffective public awareness program, which did not adequately educate the public or emergency response officials on how to respond to a suspected natural gas leak; and (3) inadequate integrity management program, which did not appropriately assess and address risk in its Mississippi Division pipeline system.

Ntsbnumber: PLD24FR003

Report Number: PIR-26-01

Addressee Name: ATMOS Energy Corporation

Addressee Status: Open - Initial Response Received

Addressee Organization Type: P-Private Industry

Communication Date: 2026-03-26

Communication Type: Transmittal Letter

Communication Contents: The National Transportation Safety Board (NTSB) is an independent federal agency charged by Congress with investigating every civil aviation accident in the United States and significant accidents in other modes of transportation—railroad, highway, marine, and pipeline. We determine the probable cause of the accidents and issue safety recommendations aimed at preventing future accidents. In addition, we carry out special studies concerning transportation safety and coordinate the resources of the federal government and other organizations to assist victims and their family members affected by major transportation disasters. We are providing the following information to urge Atmos Energy Corporation to act on the safety recommendation in this letter because we believe your organization can help reduce the risk of future accidents. For more information about the NTSB and our recommendation process, please see the attached one-page summary. This letter also includes information about our March 12, 2026, report, Atmos Energy Corporation Natural Gas-Fueled Home Explosions and Fires, Jackson, Mississippi, January 24, 2024, and January 27, 2024, NTSB/PIR-26-01. The details of this accident investigation and the resulting safety recommendations may be found in the attached report, which can also be accessed at http://www.ntsb.gov. As a result of this investigation, we identified the following safety issues: • Compression coupling leaks that the natural gas distribution operator had identified and left unrepaired. • Insufficient leak management program, which did not determine appropriate monitoring timelines for leaks in adverse-soil conditions. • Ineffective public awareness program, which did not adequately educate the public or emergency response officials on how to respond to a suspected natural gas leak. • Inadequate distribution integrity management program, which did not appropriately assess and address risk in its pipeline system. • Absence of natural gas detection alarms in buildings, which left occupants vulnerable to the dangers of unrecognized gas leaks. Accordingly, the NTSB makes the following safety recommendations to Atmos Energy Corporation (additional information regarding this recommendation can be found in the noted section of the report): • Develop and implement a program to locate and replace all mechanical couplings and mechanical joints located in expansive soils that are not resistant to pipe pullout with couplings and joints developed specifically for those conditions. The program should establish and make public the project milestones and timeline. (P-26-3) (See section 2.2.) • Update your companywide leak management program procedures to require weekly monitoring of nonhazardous (grade 2 or grade 3) belowground leaks identified in locations with adverse-soil conditions (such as water-saturated soil, flooding, drought, frozen ground, or settlement). (P-26-4) (See section 2.3.) • After completing the action described in P-26-4, implement a training program to maintain employee and contractor proficiency on the updated procedures. (P-26-5) (See section 2.3.) • Develop and implement a program to provide more frequent training to emergency response officials in all the distribution areas that you serve, including training on how to respond to natural gas-leak calls, and monitor the program for effectiveness. (P-26-6) (See section 2.4.) • Require your technicians who identify but do not repair a belowground natural gas leak to immediately notify people near the unrepaired leak that (1) the hazard potential of a leak can change over time, and (2) they should evacuate and then call 9 1 1 and Atmos Energy Corporation every time they smell natural gas odorant. (P-26-7) (See section 2.4.) • Develop and implement a program to proactively identify and collect missing service-line information for all your operating divisions. The program should (1) identify one or more methods for gaining additional system data and (2) establish and make public the milestones and timeline for acquiring the unknown system data. (P-26-8) (See section 2.5.) • Transition from a relative-risk model to a probabilistic distribution integrity management risk model. (P-26-9) (See section 2.5.) • Develop and implement a program that makes natural gas alarms available to members of the public who reside in your distribution areas. (P-26-10) (See section 2.6.) The NTSB is vitally interested in these recommendations because they are designed to prevent accidents and save lives. We would appreciate a response within 90 days of the date of this letter, detailing the actions you have taken or intend to take to implement these recommendations. When replying, please refer to the safety recommendations by number (Safety Recommendation P-26-3 through -10). We encourage you to submit your response to ExecutiveSecretariat@ntsb.gov. If your reply, including attachments, exceeds 20 megabytes, please e mail us at the same address for instructions on how to send larger documents. Please do not submit both an electronic copy and a hard copy of the same response. All communications regarding safety recommendations are stored by the NTSB and viewable by the public. Please do not send privileged or confidential communications in response to this recommendation. Responses marked as confidential or privileged (or similar designations) will be considered nonresponsive. In the likely event that your organization uses auto generated and/or preformatted confidentiality statements on letterhead or outgoing e-mails, please include a statement in your letter indicating that the information can be publicly released. If you have concerns about this protocol, please contact us at ExecutiveSecretariat@ntsb.gov. From Pipeline Investigation Report PIR-26-01 “Atmos Energy Corporation Natural Gas Fueled Home Explosions and Fires Jackson, Mississippi January 24, 2024, and January 27, 2024” published on March 26, 2026: 2.3 Insufficient Leak Management Program Leak Repair and Leak Reevaluation The leaks Atmos identified and classified on Bristol Boulevard (a grade 2 leak) and Shalimar Drive (a grade 3 leak) became hazardous before Atmos’s leak management program procedures required them to be reevaluated or repaired. Atmos’s Mississippi procedures required a grade 2 leak to be reevaluated at least once every 6 months and repaired within one calendar year (but no later than 15 months). The accident on Bristol Boulevard occurred about 2 months after Atmos identified the grade 2 leak there, which was about 4 months before Atmos procedures required its technicians to reevaluate the leak and about 13 months before Atmos procedures required its technicians to repair it. Atmos’s Mississippi procedures required a grade 3 leak to be reevaluated during the next scheduled survey or within 15 months, whichever came first, and repaired or cleared within 36 months. The accident on Shalimar Drive occurred about 2 months after Atmos identified the grade 3 leak there, which was about 13 months before Atmos procedures required its technicians to reevaluate the leak and about 34 months before Atmos procedures required its technicians to repair or clear it. After the two accidents, Atmos updated its companywide leak management program to reduce the reevaluation and repair timelines for all nonhazardous natural gas leaks to every 30 days and within 6 months, respectively. Leak Monitoring Between November 2023 and January 2024, when weather conditions in Jackson adversely affected the soil, changing the natural gas migration patterns of at least 2 of the 289 open (unrepaired) leaks in the city (leaks open on the day of the Bristol Boulevard accident), Atmos’s Mississippi leak management program procedures did not prompt employees to monitor the open leaks. However, unlike Atmos’s Mississippi procedures, Atmos’s procedures for classif

Addressee Organization Type: P-Private Industry

Communication Date: 2026-06-24

Communication Type: Official Correspondence

Communication Contents: -From John McDill, Senior Vice President Utility Operations: Atmos Energy maintains a comprehensive and ongoing training program for employees focused on leak investigation, classification, and response. For material changes to our procedures, we develop and deploy training for all employees, respective leaders, and inform contractors that are expected to perform and oversee those tasks about the respective changes. With respect to our leak management program outlined in our response to Recommendation P-26-4, Atmos Energy has completed that training for employees and informed contractors about any specific material changes to our procedures. In addition to specific training for material procedure changes, Atmos Energy’s training program is supported by annual refresher training, field observations, and quality assurance activities to promote consistent application of procedures in operational settings. Atmos Energy will continue to provide regular training and reinforcement to maintain proficiency and consistency in leak management practices, consistent with applicable procedures and regulatory expectations. For example, Atmos Energy recently completed refresher training on leak cause to support consistent causation determination which in turn provides improved data for risk modeling and system knowledge. We believe the training we have provided satisfies the intent of this Recommendation. Accordingly, we ask that the NTSB close this Recommendation as acceptable.