TROY, Mich. — Four individuals have been charged in connection with the tragic death of 5-year-old Thomas Cooper, who was killed when a pressurized oxygen chamber exploded at the Oxford Center in Troy, Michigan, on January 31. The explosion, described as a “fully involved fire” that incinerated the young boy, has led to charges ranging from second-degree murder to involuntary manslaughter.
According to Michigan Attorney General Dana Nessel, Thomas was pronounced dead at the scene after the explosion. His mother, who attempted to rescue him, suffered burn injuries in the process. Nessel stated that a “single spark” ignited the fire, which took Thomas’s life within seconds.
The charges have been brought against Tamela Peterson, 58, the founder and CEO of the Oxford Center; Gary Marken, 65, the facility manager; Gary Mosteller, 64, the safety manager; and Aleta Moffitt, 60, the operator of the chamber at the time of the explosion. Peterson faces second-degree murder charges, while Marken and Mosteller have been charged with both second-degree murder and involuntary manslaughter. Moffitt faces involuntary manslaughter charges, as well as charges of falsifying medical records.
Each of the accused entered not guilty pleas at their arraignments in Troy District Court on Tuesday. Bonds have been set at $2 million for Peterson, $250,000 for Marken and Mosteller, and $100,000 for Moffitt. Concerns over Peterson’s access to substantial financial resources led to her high bond amount.
During the arraignments, defense attorneys for the accused expressed surprise at the severity of the charges and the bond amounts. Raymond Cassar, representing Marken, called the second-degree murder charge a “total shock” and emphasized that the incident was an accident. He added that “our thoughts and prayers go out to the family of this little boy” but reminded the public that his client is presumed innocent. Similarly, Ellen Michaels, representing Moffitt, expressed sympathy for the family while calling for fairness in the legal process.
The death of Thomas Cooper has sparked widespread outrage, particularly because the therapy he was receiving was deemed medically unsupported. According to Attorney General Nessel, the child had been receiving hyperbaric oxygen therapy for conditions such as sleep apnea and ADHD, which are not approved by the U.S. Food and Drug Administration (FDA) for such treatment. The FDA has cleared hyperbaric oxygen therapy for only 13 specific conditions, including severe burns and decompression sickness. Nessel stressed that the therapy provided to Thomas was not covered by insurance because it did not meet medical standards, further underscoring that the Oxford Center operated as a for-profit business without regard for patient safety.
The tragedy has also highlighted significant safety violations at the Oxford Center. Nessel revealed that a maintenance check had not been conducted on the chamber on the day of the explosion. Furthermore, there was no medical doctor present at the facility, and the chamber was operated by a technician who was not licensed. Experts consulted by investigators described the center’s practices as “horrifying,” noting that the hyperbaric chambers had been used far beyond their expected service life and that crucial safety measures were routinely ignored.
The Oxford Center has since issued a statement claiming that patient safety is its “highest priority” and that it would fully cooperate with investigations into the explosion. The center also emphasized that it had been operating for more than 15 years without any prior incidents of this nature. However, the facility’s accreditation status has come into question. As of February 2025, the Oxford Center was not listed among the facilities accredited by the Undersea and Hyperbaric Medical Society, an organization that sets safety standards for hyperbaric therapy centers.
While the investigation into the explosion continues, the legal proceedings against those charged are expected to draw significant attention. The case has already raised important questions about the safety and regulation of hyperbaric therapy centers, particularly those offering treatments beyond the FDA-approved list of conditions.
As the legal process unfolds, the Cooper family, attorneys, and the community continue to grapple with the loss of a young child whose life was tragically cut short due to what many believe was preventable negligence.
