Democratic Sen. Ed Markey is calling on federal investigators to “turn over every stone” in investigating the massive Columbia Gas explosion that set neighborhoods ablaze last month outside of Boston.
“We need to turn over every stone and shine a light on the workings of this company and the entire industry, so that people can both trust that their gas system is safe and verify that nothing like this will ever happen again,” said Markey on Thursday after the National Transportation Safety Board issued the results of its preliminary investigation into the Sept. 13 natural gas explosion.
The NTSB findings read like a timeline of events leading up to the explosions, which killed one person and injured over 20 others, including several first responders, according to the findings.
At least five homes were completely leveled by the incident, and 131 structures in three towns damaged by fires caused by natural gas appliances, the NTSB said.
“The release of the preliminary report raises more questions than answers about how the Merrimack Valley disaster occurred, and I will not stop until we get each and every answer,” said Markey.
Markey and fellow Democratic Sen. Elizabeth Warren, both from Massachusetts, initiated their own probe into the Columbia Gas explosion, finding that the utility’s safety and response plans contained “critical deficiencies” in dealing with the natural gas high-pressure event that resulted in the explosions and fires last month.
The senators sent a letter to the CEOs of Columbia Gas and its parent company NiSource last week, asking for answers to questions regarding the safety plan deficiencies they had found.
The NTSB findings show that a work crew had been changing out a part of the aging natural gas distribution system before the explosion. The crew had triggered an old sensor, which caused natural gas to flow at extremely high pressure.
The event triggered an alarm at the company’s monitoring station hundreds of miles away in Columbus, Ohio, which could not take direct action to resolve it.
The Ohio monitoring center had “no control capability to close or open valves,” the findings read. “[I]ts only capability was to monitor pressures on the distribution system and advise field technicians accordingly."
The Columbia Gas controller’s office followed company protocol by calling the Meters and Regulations group in Lawrence, Mass.
That call was soon followed by a local resident making the first 9-1-1 call to Lawrence emergency services at 4:11 p.m., read the preliminary findings.
The NTSB found that the company approved the work plan for the crew that tripped the sensor, but "did not account for the location of the sensing lines or require their relocation to ensure the regulators were sensing actual system pressure."
The NTSB investigation is still ongoing, but the agency said it will include an analysis of the crew's work package and its preparation and execution in future investigations, according to the report.
The safety probe will also look at coordination between emergency responders and Columbia Gas.