Federal safety investigators issued a subpoena to Pennsylvania's public utility regulator on Monday for documents related to a fatal explosion at a chocolate factory, escalating a months-long legal dispute over the state agency's authority to share the sensitive information.
The National Transportation Safety Board said Monday that the Pennsylvania Public Utility Commission has refused to provide inspection and investigation reports for UGI Utilities Inc. That's the natural gas utility at the center of the probe into the March 24 blast at the R.M. Palmer Co. plant in West Reading.
The powerful natural gas explosion killed seven people.
THe NTSB found that natural gas leaked from the defective fitting at the chocolate factory, where the massive explosion leveled one building, heavily damaged another, and killed seven people.
Investigators previously said they are looking at a pair of gas leaks as a possible cause of or contributor to the blast.
The interagency dispute over five years' worth of UGI records involve a conflict between state and federal law. The Public Utility Commission says state law protects the reports from public disclosure.
