Columbia Gas, the utility behind the deadly 2018 Merrimack Valley gas explosions, will pay a $53 million fine and be sold by its parent company, NiSource, after agreeing to plead guilty in connection with the disaster, authorities announced Wednesday.

U.S. Attorney Andrew Lelling said in a press conference that Columbia Gas had agreed to plead guilty to felony violation of the Pipeline Safety Act after a federal investigation found "wholesale management failure" at the utility led to the disaster.

"I'm glad they're pleading guilty," said Lawrence resident Catalina Piccinini, who had to be evacuated amid the chaos. "I hope good can come from this and the city of Lawrence can recover."

Columbia Gas will pay a $53 million criminal fine for breaking a federal pipeline safety law and plead guilty to causing a series of natural gas explosions in Massachusetts that killed one person and damaged dozens of homes, federal officials announced Wednesday.

NiSource has also agreed to take steps to sell off Columbia Gas and stop doing business in Massachusetts, Lelling said.

Moreover, the companies have agreed to pay the federal government an amount equal to any profits made from the sale of the utility to a third party.

JUST IN: Columbia Gas will pay a $53 million fine & be on probation for 3 yrs according to plea agreement just released. Standing by for press conference with U.S. Attorney. @NBC10Boston @necn pic.twitter.com/RmBztNSmZh — Abbey Niezgoda NBC10 Boston (@AbbeyNBCBoston) February 26, 2020

Eversource Energy announced later Wednesday it reached an agreement to purchase the assets of Columbia Gas for $1.1 billion from NiSource. Until that acquisition is complete, an independent monitor chosen by authorities will monitor the activities of Columbia Gas to ensure it is compliant with regulations.

"We're here because this investigation found that Columbia Gas, through a pattern of flagrant indifference in the face of extreme risk to the life and property, knowingly violated minimum safety standards," Lelling said.

"This disaster was caused by wholesale management failure at Columbia Gas."

The Sept, 13, 2018 gas explosions killed 18-year-old Leonel Rondon and injured 25 others, set more than 100 homes on fire and displaced 8,000 people in Andover, North Andover and Lawrence.

Many people were without gas, including heat and hot water, throughout last winter. Residents were given space heaters and hotplates while crews worked to restore 48 miles of pipeline.

The National Transportation Safety Board said Tuesday they are recommending stronger nationwide requirements for natural gas systems following last September’s natural gas explosions and fires in Massachusetts.

Lelling added that the findings were in line with those of the National Transportation Safety Board, which found that the utility used "inadequate" and "deficient" procedures in a pipeline project.

Lelling said the company knew about risks posed by overpressurization of gas pipelines and and failed to maintain a system of centralized record keeping, contributing to the disaster.

A tweet from FBI Boston on Wednesday morning said Columbia Gas of Massachusetts is being held "criminally & financially accountable" for the explosions and fires.

The U.S. Attorney's Office earlier said in a tweet that Columbia Gas has agreed to plead guilty to violating the Pipeline Safety Act.

#BREAKING: Columbia Gas of Mass. has agreed to plead guilty to violating the Pipeline Safety Act following investigation into catastrophic gas explosions in Sept. 2018 in #MerrimackValley. Details to follow at 10:30 press conference w/ USA #Lelling, @DOTInspectorGen & @FBIBoston — U.S. Attorney MA (@DMAnews1) February 26, 2020

A spokesman for Columbia Gas of Massachusetts said in a statement Wednesday that the company takes full responsibility.

"Today’s resolution with the U.S. Attorney’s Office is an important part of addressing the impact," the statement said. "Our focus remains on enhancing safety, regaining the trust of our customers and ensuring that quality service is delivered."

Lawrence Mayor Dan Rivera praised the plea deal while speaking to the media later in the day, saying it will be a "great day" when Columbia Gas no longer exists.

"This agreement will bring some much-needed solace to those affected," Rivera said.

Residents were forced out of their homes and into shelters as their homes and belongings burned in what one horrified fire chief described as "Armageddon." For months, Merrimack Valley homeowners lived in reception centers, trailers and hotel rooms as they awaited the approval to return home and start over.

Lawrence resident Brenda Rozzi is among the many still impacted by the trauma of the gas explosions.

"People still do not feel comfortable in the city of Lawrence," Rozzi said. "I am president of my neighborhood association and people just talk about it all the time. You just never know what's going to happen next."

Lawrence Mayor Dan Rivera spoke out Friday on the response of Columbia Gas amid a series of gas-fueled explosions and fires across Merrimack Valley in Massachusetts.

Columbia Gas agreed to pay $143 million to settle all class action lawsuits in connection to the disaster.

The National Transportation Safety Board released its final report on the disaster in October of 2019, saying the probable cause of the overpressurization that led to the gas explosions was Columbia Gas' "weak engineering management that did not adequately plan, review, sequence, and oversee the construction project" that led to the abandonment of a cast iron gas main without first relocating regulator sensor lines to the new main.

Another contributing factor was that the gas distribution system was designed and operated "without adequate overpressure protection," the report said.

Columbia Gas is scheduled to plead guilty on March 9.

SHOCKING IMAGES: Gas-Related Explosions and Fires in the Merrimack Valley

The Associated Press contributed to this report.