P-25-012
P-25-012
NTSB safety recommendation P-25-012.
TO THE COMMON GROUND ALLIANCE: Identify and pursue opportunities for improving adoption of your best practices on 811 center membership, including updating your best practices guide and encouraging states to adopt the updated guidelines.
Priority: CLASS II
Overall Status: Closed - Acceptable Action
Issued Date: 2025-04-08
Adopted Date: 2025-03-18
Overall Date Closed: 2026-04-15
Synopsis: This report discusses the March 24, 2023, natural gas–fueled explosion and fire at Building 2 of the R.M. Palmer Company, a candy manufacturer located in West Reading, Pennsylvania. The explosion destroyed the manufacturer’s Building 2 and caused significant structural damage to its adjacent Building 1 and other surrounding structures. In total, 7 people were killed, 10 people were injured, and 3 families were displaced from a neighboring apartment building. Safety issues identified in this report include degradation of a retired service tee, insufficient consideration of threats to pipeline integrity, the risk associated with unmarked private pipeline assets crossing public rights-of-way (for example, a public street), delayed evacuation of Building 2 despite detection of natural gas, natural gas safety messaging that may not reach certain members of the public, insufficient guidance on gas leak emergency procedures, absence of natural gas detection alarms in commercial buildings, and insufficient accessibility of gas distribution line valves. As part of this investigation, the National Transportation Safety Board issued recommendations to the Pipeline and Hazardous Materials Safety Administration, the Occupational Safety and Health Administration, 50 states along with the Commonwealth of Puerto Rico and the District of Columbia, the Commonwealth of Pennsylvania, the Pennsylvania Public Utility Commission, the American Gas Association, the American Petroleum Institute, the Gas Piping Technology Committee, the Common Ground Alliance, the International Code Council, the National Fire Protection Association, UGI Corporation, and R.M. Palmer Company.
Probable Cause: The National Transportation Safety Board determines that the probable cause of the explosion was degradation of a retired 1982 Aldyl A polyethylene service tee with a Delrin polyacetal insert that allowed natural gas to leak and migrate underground into the R.M. Palmer Company candy factory buildings, where it was ignited by an unknown source. Contributing to the degradation of the service tee and insert were significantly elevated ground temperatures from steam escaping R.M. Palmer Company’s corroded underground steam pipe, located near the service tee, that had been unmarked and cracked. Contributing to the steam pipe crack was soil movement and R.M. Palmer Company’s lack of awareness of the pipe’s corroded state. Contributing to the natural gas leak was UGI Corporation’s lack of awareness of the nearby steam pipe, which led to an incomplete integrity management program evaluation that did not consider or manage the risk posed by the steam pipe. Contributing to the accident’s severity was R.M. Palmer Company’s insufficient emergency response procedures and training of its employees, who did not understand the hazard and did not evacuate the buildings before the explosion.
Ntsbnumber: PLD23LR002
Report Number: PIR-25-01
Addressee Name: Common Ground Alliance
Addressee Status: Closed - Acceptable Action
Addressee Date Closed: 2026-04-15
Addressee Acronym: CGA
Addressee Organization Type: A-Associations
Communication Date: 2025-04-08
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 the Common Ground Alliance 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 18, 2025, report, UGI Corporation Natural Gas-Fueled Explosion and Fire, West Reading, Pennsylvania, March 24, 2023, NTSB/PIR-25/01. 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: • Degradation of a retired Aldyl A service tee that was accelerated by elevated ground temperatures from a corroded and cracked steam pipe nearby. • UGI Corporation’s insufficient consideration of pipeline integrity threats, particularly Aldyl A service tees with Delrin inserts at elevated temperatures. • Presence of unmarked and unreported private assets crossing public rights-of-way, excluding them from the Pennsylvania One Call System and increasing the risk of damage to them. • Delayed evacuation of Palmer’s Building 2 despite detection of natural gas by employees and others. • Natural gas safety messaging from pipeline operator public awareness programs that may not reach certain members of the public. • Insufficient guidance on natural gas emergency procedures. • Absence of natural gas alarms in commercial buildings. • Insufficient accessibility of gas distribution line valves. Accordingly, the NTSB makes the following safety recommendation to the Common Ground Alliance (additional information regarding this recommendation can be found in the noted section of the report): • Develop guidance for natural gas pipeline operators to ensure that their distribution integrity management programs appropriately assess and address threats to plastic pipelines posed by nearby assets that may elevate the temperature of the environment near the pipeline. (P-25-12) (See section 2.4.) The NTSB is vitally interested in this recommendation because it is 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 this recommendation. When replying, please refer to the safety recommendation by number (Safety Recommendation P-25-12). 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. The attached letter from the NTSB Chairman provides information about the March 18, 2025, report UGI Corporation Natural Gas-Fueled Explosion and Fire, West Reading, Pennsylvania, March 24, 2023, PIR-25-1. 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. The NTSB is vitally interested in this recommendation because it is 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 this recommendation. When replying, please refer to the safety recommendation by number (for example, P-25-12). We encourage you to submit your response to ExecutiveSecretariat@ntsb.gov. If your reply exceeds 20 megabytes, including attachments, 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. From the report UGI Corporation Natural Gas-Fueled Explosion and Fire, West Reading, Pennsylvania, March 24, 2023, PIR-25-1: 2.4 Unmarked Private Assets in Public Rights-of-Way Pennsylvania’s Underground Utility Line Protection Law requires owners and operators of underground lines serving one or more customers to register with PA One Call (PA One Call 2024). Based on the definitions within Amended Pennsylvania Act 287, the Underground Utility Line Protection Law, Pennsylvania did not require Palmer to be a member of PA One Call. The Common Ground Alliance’s (CGA) Best Practices Guide contains a uniform pavement marking color code, which Pennsylvania used. The code includes steam pipelines along with other potentially dangerous materials transported by pipeline such as gas, oil, petroleum, or gaseous materials. The guide recommends marking the location of underground steam pipes with yellow pavement paint. The CGA guide further explains in Best Practice 3-32 that owners and operators of private assets who are not members of an 811 center like PA One Call will not be notified of a planned excavation, and the center will not locate their assets. Had Palmer’s privately owned steam pipelines been registered with PA One Call, these assets would have been identified and marked with a uniform pavement marking as recommended by CGA. Pavement markings indicating the location of Palmer’s steam pipelines as well as UGI assets would have been the best practice to alert anyone excavating near the steam pipe of its presence before they began digging. Palmer’s condensate pipe, chocolate pipes, and steam pipe underneath Cherry Street crossed a public right-of-way. Public rights-of-way are subject to excavation not only for utility work, but also for building construction and road work. The entities that perform this work can include utility companies, private contractors, and homeowners. The NTSB concludes that the omission from PA One Call of certain assets transporting high-temperature materials like steam that are located in a public right-of-way can pose a risk to anyone excavating in the vicinity. Damage to these unmarked assets can also damage and degrade nearby assets. Therefore, the NTSB recommends that the Commonwealth of Pennsylvania modify its Underground Utility Line Protection Law to require all owners and operators of pipelines transporting steam or other high-temperature materials located in public rights-of-way to register their assets with PA One Call. The best practices presented in CGA’s Best Practice Guide contain both practice statements and practice descriptions, which together provide greater detail to assist with implementation of the practices. Best Practice 3-26 offers
Addressee Acronym: CGA
Addressee Organization Type: A-Associations
Communication Date: 2025-07-30
Communication Type: Official Correspondence
Communication Contents: -From Sarah K. Magruder Lyle, President and CEO: The Common Ground Alliance (CGA) respectfully submits this response to the National Transportation Safety Board’s (NTSB) letter dated May 1, 2025, concerning the incident that occurred in West Reading, PA, on March 24, 2023. CGA appreciates the NTSB’s ongoing dedication and commitment to enhancing public safety by working to reduce the risk of future incidents. The Common Ground Alliance is a member-driven association of nearly 4,000 damage prevention professionals committed to saving lives and preventing damage to North American underground infrastructure by promoting effective damage prevention practices of today and tomorrow. For over a quarter century, CGA has been the preeminent source of data and information for preventing damages to underground facilities through the shared responsibility among all stakeholders. CGA’s Best Practices have been considered the standard for the actions and behaviors that reduce underground utility excavation damage. The CGA Best Practices are agreed to by consensus of all 15 CGA stakeholder groups and designed to improve worker safety, protect vital underground infrastructure and ensure public safety during excavation activities conducted in the vicinity of existing underground facilities. In its final report (NTSB Pipeline Investigation Report PIR-25-01), the NTSB recommended that: “… Common Ground Alliance… Identify and pursue opportunities for improving adoption of your best practices on 811 center membership, including updating your best practices guide and encouraging states to adopt the updated guidelines. (P-25-12)” CGA has completed a comprehensive update of Best Practice 3.26: 811 Center Membership. The previous version of Best Practice 3.26 read as follows: Practice Statement: Any entity that furnishes or transports products or services to a third party for its use or consumption by means of an underground facility or furnishes or transports products or services for its own internal use by means of an underground facility that occupies or crosses a right-of-way or utility easement is a member of an 811 center. Practice Description: Underground damage prevention begins with a notice of intent to excavate submitted by an excavator to the appropriate 811 center. The process of notification depends on all affected member facility operators being notified of intent to excavate through the regional 811 center. Membership in the 811 center by underground facility operators ensures that potential conflicts with existing facilities that may be encountered during excavation activities are identified by using a single regional point of contact. Operators of the facilities who fail to become members of their local 811 center risk public safety and damage to their facilities, and endanger excavators who may come into contact with these aforementioned underground facilities. The following are examples of an underground facility that would probably not require 811 center membership: • The internal use of owned underground facilities to provide safe operations in controlled rights of ways, such as railroad operating corridors that facilitate the transportation of freight or passengers. • The internal use of an entity’s underground facilities by that entity solely on its own property. (Note: aboveground use of one’s rights of way or property, such as the transportation of freight or passengers by rail, is not within the purview of the CGA Best Practices.) References: • State One Call Laws, 1999 Common Ground Study On July 29, 2025, the CGA Board of Directors unanimously voted to approve a new version of Best Practice 3.26, as recommended by the Best Practices Committee. The updated version removes ambiguous and unnecessary language, and also removes language that encourages exemptions or exceptions to 811 membership. It reads as follows: Practice Statement: Any facility owner/operator that conveys or transports products or services by means of an underground facility is a member of the 811 center. This includes any facility that: • Occupies or crosses a right-of-way • Occupies or crosses a utility easement This does not include any facility that: • Is used exclusively to furnish services or commodities on a property for a person who is an owner or tenant of that property, such as homeowners. Practice Description: Notifying facility owners/operators of the intent to excavate is critical to preventing damage to underground facilities. Membership in the 811 center ensures that notifications are delivered to the owners/operators and prevents damages that risk public safety and endanger excavators who are working near those facilities. References: State One Call Laws CGA has also updated the following terms included in Best Practices Appendix A: Glossary of Terms and Definitions: • Facility: An underground or submerged conductor, pipe, or structure used to provide electric or communications service (including, but not limited to, traffic control loops and similar underground or submerged devices); or an underground or submerged pipe used in carrying, providing, or gathering (typically between the wellhead and transmission line) gas, oil or oil product, sewage, storm drainage, steam, water, or other substance, and appurtenances thereto. • Facility Owner/Operator: Any utility, municipality, authority, political subdivision, or other person or entity who owns, operates, or controls the operation of an underground line/facility. • Membership: Persons who participate in an 811 center because they have a statutory responsibility to protect lines or facilities, or because they have an interest in the protection of lines or facilities. In addition, the NTSB recommends that CGA encourage states to adopt this updated practice. We are committed to distributing, educating, and communicating to our state partners, including 811 centers, regional partners and all damage prevention stakeholders about the importance of adopting this updated practice. CGA would like to emphasize, however, that requiring adherence to this practice – and CGA Best Practices in their entirety as a minimum standard across all stakeholder groups – depends on these practices being incorporated into each state’s one call law. One of the most critical steps to reducing damages to underground infrastructure is encouraging all stakeholders to adhere to Best Practices. CGA is committed to working with our state partners to update and adopt this important language. We appreciate the NTSB’s work in ensuring the safety of those who live and work near the critical infrastructure that our communities depend on every day.
Addressee Acronym: CGA
Addressee Organization Type: A-Associations
Communication Date: 2026-04-15
Communication Type: Official Correspondence
Communication Contents: Our investigation of this incident found that if Palmer’s privately-owned steam pipelines had been registered with PA One Call, they would have been identified and marked with a uniform pavement marking, as recommended by the CGA. Pavement markings indicating the location of Palmer’s steam pipelines, as well as UGI assets, would have been the best way to alert anyone excavating near the steam pipe of its presence before they began digging. We understand that, in July 2025, the CGA Board of Directors approved revisions that are now reflected in The Definitive Guide for Underground Safety and Damage Prevention Best Practices 22.0. We are pleased to learn that you are updating your process to reflect updates in the electronic version as they are approved. We also understand that, as a 501(c)(3) organization, the CGA does not advocate for legislation; however, you wrote that the CGA will continue distributing, educating, and communicating to your state partners, including 811 centers, regional partners, and all damage-prevention stakeholders about the importance of adopting these updated practices. Additionally, National Transportation Safety Board staff will present at the 2026 CGA Conference and Expo. These actions meet the intent of this recommendation. Accordingly, the Board has voted to classify Safety Recommendation P-25-12 CLOSED-- ACCEPTABLE ACTION.
This material provides agency context. It does not replace binding regulatory text, and its legal effect depends on the underlying authority and facts.