The city of Wilmington on Monday denied responsibility for the deaths of three firefighters in a 2016 blaze, which left three others injured and sparked a federal civil rights lawsuit targeting four former officials over the implementation of a controversial policy known as “rolling bypass.”

Attorneys for the city asked a Delaware federal judge to dismiss the suit in court papers filed late Monday, saying the plaintiffs had failed to assert any due process violations in the case.

According to the city, the policy, which mandated that certain fire engines be closed in the event of staffing shortages, dealt with the allocation of public resources and was not subject to a constitutional challenge by the families of the deceased firefighters and their injured colleagues.

“Decisions about safety standards for public employees and the benefits provided when they are harmed in the line of duty are matters of state and local law and are not determined through federal lawsuits that would burden public entities with millions of dollars of discovery and litigation costs and have federal judges and juries dictate workplace conditions by interpreting the contours of the substantive due process clause,” the city's McCarter & English attorneys wrote in a 31-page brief.

Former Mayors Dennis P. Williams and James M. Baker and former fire Chiefs Anthony S. Goode and William Patrick Jr. all filed separate motions to dismiss the suit, claiming that they were shielded from liability for actions they had taken in their official capacities with the city.

The lawsuit, filed in August, accused the officials of ignoring repeated warnings about the policy from city council members and the local firefighters union, and it seeks to hold them liable for substantive due process violations under the state-created danger doctrine.

The case stems from a September 2016 residential fire in Wilmington's Canby Park neighborhood, which killed Lt. Christopher Leach and senior firefighters Jerry Fickes and Ardythe Hope and seriously injured three others. According to the complaint, the engine closest to the fire was shut down under “rolling bypass,” leaving the firefighters without the water they needed to combat the blaze in the rear basement of the home.

Beatriz Y. Fana-Ruiz, who occupied the home at the time, has been indicted on multiple counts of arson, murder, assault and reckless endangering in connection with the fire, according to court documents.

Thomas S. Neuberger, who represents the firefighters and their families, has said ”blood is on the hands” of former Mayors Baker and Williams. Neuberger, founder of The Neuberger Firm in Wilmington, last year sued Delaware state officials over alleged lapses that led to the deadly prison takeover at James T. Vaughn Correctional Center, in a case that later settled for $7.5 million.

Current Mayor Mike Purzycki, who is not named in the lawsuit, responded by accusing Neuberger and the other plaintiffs' attorneys of misrepresenting the facts of the case in order to obtain a “quick cash settlement” from the city.

Purzycki, who took office in January 2017, said the city expected to pay more than $11 million to the families and the surviving firefighters to cover medical costs and related benefits. He has denied allegations that rolling bypass and staffing decisions contributed to the tragedy.

On Monday, the city said that it was neither the cause nor the “catalyst” for the fire and thus could not be held liable under the “state-created danger” theory. According to the city's filing, the two fire engines that responded to the scene were positioned in the front of the house, despite reports from Leach that the “heart” of the fire was located in the rear.

Neuberger said Tuesday that the city had simply “recycled the previous unsuccessful arguments” used by the state in the earlier prison lawsuit. He said his team was preparing to file a 110-page answering brief in January.

“When it considers the law we present in January, we expect that our respected district court will find that all defense arguments lack merit in this case of great public concern,” Neuberger said in a statement.

The case, in the U.S. District Court for the District of Delaware, is captioned Speakman v. Williams.