The family of Thomas Cooper, the 5-year-old killed during an explosion in a hyperbaric chamber in Troy, Michigan, has filed a $100 million lawsuit naming the facility where it took place, the equipment manufacturer and others as defendants. 

Fieger Law says the family seeks not just financial damages but also "answers from those responsible for why they allowed this to happen." Fieger Law managing partner James Harrington discussed the lawsuit and provided photos of the fire's aftermath during a press conference Monday at the firm's Southfield office. 

The Cooper family had retained Fieger Law soon after the fatal incident. 

"We have uncovered new information which shows this was not a tragic accident," the attorneys said. "It was a foreseeable, inevitable, and virtually certain result of Defendants' callous indifference to human life." 

Thomas was killed in the fire that erupted the morning of Jan. 31 while he was in a treatment chamber. His mother was in the room with him at the time and also had injuries to her arms from the explosion. 

Michigan Attorney Dana Nessel later said no medical doctor or safety supervisor was present during the treatment and that the treatment was not performed by a licensed technician. Yearly inspections of the hyperbaric chamber, as recommended by the manufacturer, were reportedly not conducted and an essential patient-worn grounding strap was not used.  

"The Oxford Center routinely operated sensitive and lethally dangerous hyperbaric chambers beyond their expected service lifetime and in complete disregard of vital safety measures and practices considered essential by medical and technical professionals," Nessel said. 

Entities named in the suit are Sechrist Industries, manufacturer of the hyperbaric chamber; Oxford Hyperbaric Oxygen Therapy Center LLC, the facility where the incident happened; Oxford Kids Foundation, a Michigan nonprofit connected to the center; and Office Ventures Troy LLC, the property owners. Individual executives and employees connected with Oxford were also named, including founder and CEO Tamela Peterson and technician Aleta Moffitt, who was the operator of the hyperbaric chamber at the time of the boy's death, along with safety and training director Jeffrey Mosteller and operations director Gary Marken.

CBS News Detroit has reached out to California-based Sechrist Industries for comment. 

Peterson was earlier charged with second-degree murder and involuntary manslaughter as a result of the incident. Mosteller and Marken have also been charged with second-degree murder and involuntary manslaughter. Moffit was charged with one count of involuntary manslaughter and one count of intentionally placing false information on a medical record as a medical provider.   

A hyperbaric chamber is an enclosed space that provides oxygen therapy amid higher-than-usual air pressure.