Morgan & Morgan Fort Lauderdale partner Frank Petosa has filed the first lawsuit over damages caused by dozens of gas explosions that rocked three Massachusetts communities.

The law firm filed the class action Tuesday in Essex County Superior Court in Massachusetts on behalf of residents of the Merrimack Valley region, including the 8,600 forced to evacuate after gas line operator Columbia Gas of Massachusetts cut their service. The explosions Sept. 13 in the towns of Andover, North Andover and Lawrence killed a teenager and injured more than 20 others.

The National Transportation Safety Board is investigating the cause of the explosions. According to a letter sent Monday to Columbia Gas officials from legislators including U.S. Sens. Elizabeth Warren and Edward Markey, both Massachusetts Democrats, the gas pressure was 12 times higher than it should have been in the pipes.

The lawsuit was filed on behalf of a Lawrence resident who was unable to get her dog from her home and spent the night on a stranger's floor after the explosions and fires erupted. It seeks compensation for lost property value and income, relocation costs and other monetary damages, as well as injunctive relief and punitive damages.

“Our goal is to ensure residents in these three towns have access to justice and that the company is held accountable,” Petosa said during a conference call with reporters Tuesday. “What we're seeking to do is to hold both companies accountable for what happened and ensure the members of the class have access to justice and compensation for any losses they've suffered.”

Petosa, a member of the firm's complex litigation group, filed suit along with colleagues Rene Rocha in New Orleans and Tyler Church in Boston.

Ken Stammen, a spokesman for Columbia Gas parent NiSource Inc., wouldn't comment on the litigation, though he noted the company is “fully committed to responding to the needs of people who are suffering because of this incident.” Columbia Gas previously said it plans to replace 48 miles of cast iron and bare steel in its distribution lines with modern plastic pipes as part of a program in collaboration with the governor's office.

“This unprecedented event requires unprecedented action,” said NiSource CEO Joe Hamrock in a statement Sunday. “We lost the trust of this community and are 100 percent committed to restoring safety, confidence and peace of mind for everyone in this community. Over time, we hope to earn back the trust we lost during this incident.”

Columbia Gas also has set up a property claims process to help pay for “evacuation expenses, food spoilage, child care costs, etc.”

Two other law firms, New York's Bragar Eagel & Squire and Los Angeles-based Glancy Prongay & Murray, are investigating potential lawsuits on behalf of shareholders of NiSource, whose stock fell on the day of the gas explosions.

The lawsuit brings claims of strict liability for ultra-hazardous activities and negligence, alleging the gas distribution system was “poorly maintained, antiquated, obsolete and highly dangerous.” It lists prior incidences involving Columbia Gas. The Massachusetts Department of Public Utilities, for instance, has fined Columbia Gas $100,000 for improper maintenance issues over several years, and a gas line in Springfield caused an explosion that injured 21 people in 2012. Months later, a gas line operated by another NiSource subsidiary exploded in Sissonville, West Virginia.

“This is a shock to people in the area, but it is not a surprise to Columbia Gas Co.,” Robert Kennedy Jr., a partner in Morgan & Morgan's New York office, told reporters. “I've been involved in litigation against Columbia all over the country.”

During the call, Petosa said Morgan & Morgan would be conducting its own investigation to provide “another voice” to the NTSB and other government authorities. The firm's lawyers plan to be in Lawrence on Thursday for a town hall session with public officials, Kennedy said.

The lawsuit does not seek compensation for injuries, property damage or losses to businesses, all of which could be part of future individual lawsuits, Petosa said. Lawyers said their suit sought to provide more adequate relief than a compensation fund announced Tuesday by Massachusetts Gov. Charlie Baker that includes a $10 million contribution from Columbia Gas.

Kennedy said the government, and not just Columbia Gas, was at fault in this case. He also noted Morgan & Morgan was involved in lawsuits over the Deepwater Horizon oil spill litigation and gas leak cases in California, both of which had similar compensation programs.

“We found there was a collaboration, a disturbing collaboration, between the regulated industry and the regulators who were supposed to protect the public,” he said.