Natural gas leaked from a defective fitting at a Pennsylvania chocolate factory where a powerful explosion leveled one building, heavily damaged another and killed seven people, federal safety investigators said Tuesday as they sought to pinpoint a cause.
The leak at the R.M. Palmer Co. plant in West Reading was traced to a gas fitting that was installed in 1982 and was determined to have fractured, according to an investigative update released by the National Transportation Safety Board.
The fitting, made by DuPont, had a known tendency to crack, and was added to a federal government list of pipe materials with “poor performance histories" in 2007, the safety board said.
Investigators also determined there was a small leak on a natural gas fitting installed in 2021, the board said.
About 70 Palmer production workers and 35 office staff were working in two adjacent buildings at the time of the March 24 blast. Employees in both buildings told federal investigators they had smelled gas before the explosion. Workers at the plant have accused Palmer of ignoring warnings of a natural gas leak, saying the plant, in a small town 60 miles (96 kilometers) northwest of Philadelphia, should have been evacuated.
UGI Corp. provided natural gas to the factory complex via two mains. UGI has said there wasn’t any utility work going on in the area, and it detected no sudden surge in gas usage before the explosion.
Safety investigators determined that UGI replaced a service line at the Palmer plant in 2021, but kept the 1982 service tee connected to the system and fully pressurized.
The cracked fitting was less than two feet from other pipelines that ran between the two plant buildings, including a steam line, a condensate line and several pipelines filled with heated chocolate. Investigators said they also saw a crack in the steam line.
“We are not at a point to say what caused the explosion,” NTSB spokesperson Keith Holloway said Tuesday, but he said investigators are looking at the gas leaks as a possible cause or contributor.
