A federal safety board says a corroded steam pipe and a defective natural gas fitting caused a powerful explosion at a West Reading chocolate factory.

The National Transportation Safety Board met Tuesday to discuss last year’s deadly factory explosion in West Reading. But they did not vote to adopt the final report quite yet. The NTSB board said it wants to incorporate necessary changes to the final report before voting to adopt it at a later date.

NTSB holds a public hearing aimed at determining what the probable cause of the fatal explosion at the R.M. Palmer Co. chocolate plant was in March 2023.

Cascading failures involving a corroded steam pipe and a defective natural gas fitting caused a powerful explosion in 2023 at a Pennsylvania chocolate factory, killing seven workers when the company failed to evacuate,