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, while noting they have yet to determine the cause of the blast.
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.
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.