Columbia Gas—the Massachusetts utility responsible for fatal 2018 natural gas explosions and fires north of Boston—is set to plead guilty on March 9 in a U.S. court in Boston to violations of federal law

The guilty plea follows a settlement by the firm and its parent company NiSource, to pay a $53 million federal fine.

In announcing the agreement, U.S. Attorney for Massachusetts, Andrew Lelling, told reporters that the fine “is by far the largest criminal fine ever imposed under the Pipeline Safety Act." 

The explosions and fires caused by extra pressure coursing through the gas pipeline killed an 18-year-old man, injured dozens of people and damaged or destroyed more than 130 buildings in Lawrence, Andover and North Andover.

The fines will be pumped into a federal victims’ fund. NiSource also says it will forgo profits from selling its natural gas assets in Massachusetts to Eversource Energy for $1.1 billion.

NiSource says it will also implement recommendations made by the National Transportation Safety Board in the wake of the incidne related to its pipelines in six other states. 

NTSB's final report on the disaster said Columbia Gas mistakes made in the years prior to the disaster—along with the omission of a critical sensing lines package for a pipeline replacement project—led to an overpressurized distribution system.

Columbia Gas "has accepted responsibility for the tragic events of September 13, 2018,” a spokesman for NiSource wrote in an email. “Today’s plea is another step in this process, and the company continues to move forward.”