NTSB issues final report on 2023 explosion at Pa. chocolate factory that killed 7 workers

Robert Moran, The Philadelphia Inquirer on Apr 9, 2025

By clicking submit, I authorize Arcamax and its affiliates to: (1) use, sell, and share my information for marketing purposes, including cross-context behavioral advertising, as described in our Privacy Policy , (2) add to information that I provide with other information like interests inferred from web page views, or data lawfully obtained from data brokers, such as past purchase or location data, or publicly available data, (3) contact me or enable others to contact me by email or other means with offers for different types of goods and services, and (4) retain my information while I am engaging with marketing messages that I receive and for a reasonable amount of time thereafter. I understand I can opt out at any time through an email that I receive, or by clicking here

PHILADELPHIA — The National Transportation Safety Board this week made public its final report on the 2023 natural gas explosion at a West Reading chocolate factory that killed seven employees.

The March 24, 2023, explosion at the R.M. Palmer Co. factory also injured 10 people and displaced three families from a neighboring apartment building that was severely damaged. The explosion caused an estimated $42 million in damage.

The 99-page report released Tuesday — dated exactly two years after the tragic event that rocked the borough of approximately 4,500 people — cited as the “probable cause” of the explosion a degraded plastic pipe fitting that allowed natural gas to leak and migrate into the R.M. Palmer candy factory building, where it was ignited by an unknown source.

The pipe fitting — a 1982 Aldyl A polyethylene service tee — had been identified in a July 2023 NTSB report as the likely source of the leak. The fitting had been retired from use, but was still connected to natural gas.

A corroded steam pipe significantly elevated the ground temperature and led to the natural gas service tee becoming degraded, the NTSB said.

And contributing to the steam pipe’s becoming cracked were soil movement and R.M. Palmer Co.’s “lack of awareness of the pipe’s corroded state,” the NTSB said.

“Contributing to the natural gas leak was (provider UGI Utilities’) 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,” the report said.

“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,” made the accident more severe, the report said.

After the explosion, employees from both buildings described smelling gas or rotten eggs ahead of the blast.

A spokesperson for R.M. Palmer said the company was reviewing the NTSB’s report.

“Not a day goes by that we do not remember and reflect on the heartbreaking loss of several colleagues and friends on that tragic day. We continue to mourn this loss, and our thoughts and prayers are with the families affected by this tragedy,” the company said in a statement. “R.M. Palmer takes the health, safety and wellness of our employees very seriously and will continue to work tirelessly to ensure the health and safety of our employees and will proactively work with regulators to prevent any similar tragedy in the future.”

UGI Utilities Inc. released a statement saying that the natural gas provider was “carefully reviewing the final report and recommendations” and had fully cooperated with the NTSB investigation.

“What occurred at R.M. Palmer was a heartbreaking tragedy, and our deepest sympathies remain with the victims’ families, the West Reading community, and all those affected. Since the incident, UGI has remained unwavering in its commitment to providing safe and reliable natural gas service,” the statement said.

The NTSB report lists a lengthy series of recommendations for safety improvements, including raising national awareness of the risks associated with the plastic service tee and other “plastic assets” that could become degraded from elevated temperatures.

The NTSB also “recommended that UGI inventory all its plastic natural gas assets that may be in elevated temperature environments and address the risk associated with these assets.”

Other recommendations focused on improved communications and safety awareness, and recommended that the Commonwealth of Pennsylvania review and amend its statutes to facilitate sharing investigative information with the NTSB.

The report said that during the investigation, the Pennsylvania Public Utility Commission withheld some information, citing “state security nondisclosure laws.”

“Therefore, in September 2023, the NTSB removed the PA PUC as a party to the investigation, after which the PA PUC could not participate in information sharing among parties during the investigation,” the report said.

The report said the PUC had been helpful before the dispute.

Nonetheless, the NTSB had to go to court and was eventually able to gain access to the required documentation, the report said.

The PUC’s “refusal to provide investigative information pursuant to the NTSB’s federal authority added to delays in the investigation and safety recommendations,” the report said.

In a statement on the NTSB report and on steps that Pennsylvania has taken to improve safety, the PUC said it “reiterates its commitment to working with federal partners to address legal challenges” surrounding the handling of what it said was confidential information.

“Transparency and cooperation are essential to safety,” PUC Chairman Stephen M. DeFrank said in a statement.

“By continuing to bridge the gaps between state and federal frameworks, we’re not only resolving issues from the past — we’re laying the groundwork for safer, more effective responses in the future,” DeFrank said.

_____