CNN
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An investigation conducted by the National Transportation Safety Board into the explosion at an eastern Pennsylvania candy factory that left seven people dead in March revealed that natural gas was leaking from two service lines, according to a preliminary report released Tuesday.

The report found that gas was leaking from a DuPont Aldyl A service tee installed in 1982 at the R.M. Palmer Co. facility, where the deadly explosion also injured 11 others on March 24, according to the NTSB. A service tee is a fitting that connects multiple pipes together in a T-shaped configuration.

In 2021, the service tee was retired and relocated from the basement to the outside of the building but remained connected to the natural gas system fully pressurized, the NTSB noted.

“The 1982 service tee was less than 2-feet from subsurface infrastructures that ran between Palmer Buildings 1 and 2, including a steam line, a condensate line, and several heated chocolate pipelines,” the preliminary report says. “NTSB investigators observed general corrosion and a crack in the steam line when it was exposed on-scene.”

Investigators also found another smaller leak in a new service line installed in 2021.

NTSB’s report noted that the Pipeline and Hazardous Materials Safety Administration (PHMSA) in 2007 added the Aldyl A service tees with Delrin inserts, which the 1982 line had, to a list of materials with “poor performance histories relative to brittle-like cracking.”

R.M. Palmer – a manufacturer of seasonal chocolate novelties, such as Easter chocolate bunnies – said in a statement on its website that it cannot comment on the investigation details released Tuesday.

“Because we remain a party to the NTSB’s investigation, we are prohibited from commenting further on that update. We continue to be appreciative of all the work that the NTSB has done and is continuing to do,” the company said. “We remain focused on rebuilding Palmer and doing all we can to help the entire West Reading community recover.”

The release of NTSB’s preliminary findings comes nearly four months after the explosion at the West Reading, Pennsylvania, facility devasted the community and left crews on a dayslong search and rescue mission for victims. The teams used drones and heat imaging devices to navigate piles of rubble, officials said at the time.

At the time, authorities identified the victims as Amy Sandoe, 49; Domingo Cruz, 60; Xiorky D. Nunez, 30; Susan H. Halvonik, 63; Michael D Breedy, 62; Diana M Cedeno, 44; and Judith Lopez-Moran, 55.

NTSB previously told CNN that they investigate all modes of transportation, and a pipeline is considered a form of transportation that carries products because it transports natural gas.