TROY, Mich. — Four people have been charged in the death of a 5-year-old boy who was “incinerated” inside a pressurized oxygen chamber that exploded at a suburban Detroit medical facility, Michigan’s attorney general said Tuesday.

Thomas Cooper from Royal Oak, Michigan, was pronounced dead at the scene on Jan. 31 at the Oxford Center in Troy. His mother was standing next to the chamber and was injured.

“A single spark it appears ignited into a fully involved fire that claimed Thomas’s life within seconds,” Attorney General Dana Nessel said at a news conference Tuesday.

“Fires inside a hyperbaric chamber are considered a terminal event. Every such fire is almost certainly fatal and this is why many procedures and essential safety practices have been developed to keep a fire from ever occurring,” she said.

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Charges Filed Against Center’s Staff

The center’s founder and chief executive, Tamela Peterson, 58, is charged with second-degree murder. The facility’s manager Gary Marken, 65, and safety manager Gary Mosteller, 64, are charged with second-degree murder and involuntary manslaughter. The operator of the chamber when it exploded, Aleta Moffitt, 60, is charged with involuntary manslaughter and intentionally placing false medical information on a medical records chart.

All were arrested Monday pending arraignments Tuesday afternoon in Troy District Court, Nessel said.

Nessel said the defendants unscrupulously put children’s bodies at risk through unaccredited and debunked treatments, simply because it brought cash through the door. She said putting the boy in a pressurized oxygen chamber for the ailments he suffered “is not supported by medical science.”

NBC News reported that according to the family’s attorney, the boy received multiple sessions for sleep apnea and attention-deficit/hyperactivity disorder. These conditions aren’t approved by the U.S. Food and Drug Administration to be marketed as effectively treated with hyperbaric oxygen therapy — a fact reiterated by Nessel on Tuesday.

“Because these treatments were so medically unsound, patient insurance policies would not cover the use of these chambers to treat these conditions,” Nessel said. “This business was a pure cash-flow, for-profit business.”

Legal Responses and Statements

The second-degree murder charge comes as “a total shock” said Raymond Cassar, Marken’s attorney.

“For fairness, he is presumed innocent,” Cassar said. “This was a tragic accident and our thoughts and our prayers go out to the family of this little boy. I want to remind everyone that this was an accident, not an intentional act. We’re going to have to leave this up to the experts to find out what was the cause of this.”

Moffitt’s lawyer, Ellen Michaels, also extended prayers and sympathy to Cooper’s family, while asking for “patience and fairness as this process unfolds.”

“This event has had a profound impact on so many, including my client, the community, and the first responders,” Michaels said in a statement to The AP. “I pray for healing for all those affected. Aleta Moffitt is a dedicated professional with many years of experience in the healthcare industry. She has always been a committed and hardworking individual, adhering to all corporate policies and procedures while prioritizing the well-being of her patients.”

The Associated Press left a telephone message Tuesday morning seeking comment from Peterson’s attorney. An attorney was not listed for Mosteller.

A voicemail was left seeking comment from an attorney representing the Oxford Center. The AP also left a message seeking comment from the center. The Associated Press emailed attorneys representing the family for comment on the charges and did not immediately receive a response.

The Oxford Center had said in an email following the explosion that “the safety and wellbeing of the children we serve is our highest priority.”

“Nothing like this has happened in our more than 15 years of providing this type of therapy. We do not know why or how this happened and will participate in all of the investigations that now need to take place,” the center’s statement said.

Hyperbaric Therapy and Safety Concerns

Hyperbaric therapy delivers pure oxygen to a person’s body inside the pressurized chamber. That’s up to five times the amount of oxygen in a normal room, Troy Fire Lt. Keith Young said following the explosion.

“The presence of such a high amount of oxygen in a pressurized environment can make it extremely combustible,” Young said.

Nessel called Cooper’s death “an easily preventable tragedy.” A maintenance check on the chamber had not been performed that day, no medical doctor or safety supervisor was on-site and the treatment was not performed by a licensed technician. Yearly inspections had not been conducted, and “the essential patient-worn grounding strap was not used,” she said.

The FDA has cleared hyperbaric chambers to be marketed as safe and effective for a list of 13 disorders, such as severe burns, decompression sickness and non-healing wounds. The list doesn’t include many of the other disorders advertised by the Oxford Center.

The FDA also recommends that consumers only use hyperbaric centers that are inspected and accredited by the Undersea and Hyperbaric Medical Society. The Oxford Center doesn’t appear on the society’s February 2025 list of accredited facilities.

Nessel said her office extensively consulted experts on hyperbaric chambers and treatments.

“Horrifying and simple conclusions were reached,” she said. “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.”