A trio of recently demoted former FDNY chiefs have hit the city and the agency's commissioner with a suit claiming they were victims of age discrimination.

Michael Gala, 62, Joseph Jardin, 61, and Michael Massucci, 59, filed a lawsuit in Brooklyn state Supreme Court on Thursday accusing FDNY Commissioner Laura Kavanagh of attempting to "replace [them] and other senior employees with younger personnel."

The suit claims the commissioner "targeted" the three chiefs "because they were at or near the age of 60."

"[Commissioner] Kavanagh retaliated against them and created a hostile workplace," the lawsuit says. "She sought not just to end, but literally to destroy, their long and distinguished careers."

The lawsuit claims Gala and Jardin learned they were being demoted down two ranks to "Deputy Chief" roles, effective March 4, on Feb. 3.

Massucci, meanwhile, met with Kavanagh on Nov. 21 and was told he would lose his "Chief of Personnel" duties and move to the department's Bureau of Operations, according to the lawsuit.

A week later, he was informed he would be reassigned to the FDNY's Tech Services Toolroom, "with no responsibilities, subordinates or direct reports," the lawsuit charges.

Kavanagh, the suit claims, accused the three chiefs of "insubordination," but "never identified a single order of hers that any of the [chiefs] defied" or disciplined them for doing so.

The lawsuit also claims Kavanagh "has orchestrated the demotion, resignation, termination or forced retirement of more than 10 senior women and people of color" since she became first deputy commissioner of the FDNY in 2018, "often replacing them with younger, white personnel, and often men."

The three plaintiffs are seeking a return to their previous positions and compensation for salary and benefits they lost, as well as unspecified damages and attorneys' fees, the lawsuit says.

News of the three chiefs' demotions threw the FDNY into turmoil, with three top officials resigning and several FDNY chiefs forfeiting their titles to protest Kavanagh's decision.

Asked about the backlash during an appearance on "Mornings On 1" earlier this week, Kavanagh said there was "just no way, as a new leader, to get everything that we need as the largest fire department in the country done without having your own team."

"I think sometimes people forget I am new because I was at the department for almost a decade, but I am just a few months into my tenure, and I want to have my own team," she said.

"So I think that it's not easy to make tough decisions, but I think they are necessary when you come into leadership," she added.

In a statement, a spokesperson for the FDNY said, “We would refer specific questions about this lawsuit to the law department, but it is seemingly just an attempt to undermine the authority of the fire commissioner. These allegations are baseless. We stand by the departmental decisions we have made which are consistent with our commitment to further public safety and the mission of the FDNY.”

A spokesperson for the Law Department declined to comment.