Too much pressure surging through a natural gas pipeline caused a massive explosion in Massachusetts that killed one person, injured several others and set as many as 80 buildings ablaze on Sept. 13, according to federal officials.
The National Transportation Safety Board (NTSB), which is investigating the accident along with other federal and state agencies, said while it was unclear why gas was flowing into homes at unusually high rates, NTSB investigators found gas pressure sensor equipment on a decommissioned gas line, Robert Sumwalt, the agency’s chairman, said during a Sept. 16 press briefing. He said, “The investigation will answer two questions: ‘What affect if any did this have on the overpressure situation?’ And secondly, ‘why was this sensor connected to a gas line that was being placed out of service?’”