Eversource continues to call a natural gas explosion that killed a Maynard man an “isolated, tragic accident,” while the man’s family and attorneys, in a freshly filed lawsuit, argue that the utility company’s “systemic failures” had a role in his death.

Greg Sharrigan, a retired electrician, died at age 67 on Sept. 2, 2021 when a leaking natural gas line allegedly exploded at his home, killing him, as he investigated an “unusual musty smell” the family thought was “caused by recent heavy rain and their slab and rock basement.”

But in a 2023 “notice of probable violation,” the state Department of Public Utilities found a leaking gas line outside the Maynard home, in Metrowest, caused the explosion, citing Eversource for “failing to properly classify, track and respond to” previous leaks on the street.

Attorneys for the Sharrigan family, who filed a complaint and jury demand in Middlesex Superior Court on Tuesday, argue that “Eversource found the underground leak in 2018 but never fixed it, due to a series of systemic failures and a gas main replacement policy that prioritized company profits over public safety.”

The lawsuit seeks $450 million in damages.

Investigations at the local, state, and company levels also indicated that natural gas migrated from the leak, due to a “severely corroded gas main owned and operated by Eversource,” through the earth. It then pooled in the Sharrigan basement before exploding, attorneys say.

“The 2021 fire in Maynard was an isolated, tragic accident and we continue to extend our sincere sympathies to family and friends impacted by it,” Eversource said in a statement to the Herald. “We are also disappointed that we have not been able to resolve this matter with the family and remain hopeful that we can bring this matter to a fair resolution.”

The statement is similar to one the utility company provided to WBUR last August after the DPUE issued its notice of probable violation, a document that an Eversource spokesman argued “does not actually represent final findings.”

A regulatory process is still ongoing for final determinations, the spokesman told the Herald.

“They call it a one-off incident, and yet it’s an error that is continually repeated,” attorney Pete Merrigan said alongside the Sharrigan family during a virtual news conference, “and it’s an error that’s been repeated through a formula and a scheme they created focusing on profits over risks and dangers.”

The complaint and a release from the attorneys and family outlined “several recent Eversource gas line explosions,” including incidents in Fenway, Beacon Hill, Somerville, and Needham.”

The Eversource spokesman told the Herald the incidents were neither initiated by a natural gas line leak nor related to natural gas line infrastructure.

“We take very seriously our daily work to maintain our natural gas distribution system to enhance safety and reliability for all of our customers as we focus on helping the commonwealth achieve its clean energy and decarbonization goals,” the company’s statement continued.

Sharrigan’s widow Carol and sons Ethan and Jason spoke during the news conference about the pain they’ve gone through in the wake of their husband and father’s death, demanding Eversource be held accountable.

“What Eversource did is very hard for me to talk about because the pain they caused is truly unspeakable,” Carol Sharrigan said. “Nothing can ever fix this kind of damage. But I am raising my voice to prevent this from ever happening again. The public needs to know that Eversource has been cutting corners and putting lives at risk.”