A former safety manager at a Michigan hyperbaric oxygen therapy facility has been sentenced to prison following the death of a 5-year-old boy in a chamber explosion.
Jeffrey Mosteller, 66, was sentenced to between 19 months and 15 years in prison after pleading no contest to involuntary manslaughter in connection with the death of Thomas Cooper. The child died during a treatment session at the Oxford Center in Troy, Michigan, on January 31, 2025.
The case has raised serious questions about safety procedures surrounding hyperbaric oxygen therapy and whether established precautions were properly followed at the facility.
Boy Died During Hyperbaric Oxygen Treatment
Thomas Cooper was receiving hyperbaric oxygen therapy for attention deficit hyperactivity disorder (ADHD) and sleep apnea when a fire began inside the chamber.
The oxygen-rich environment allowed the fire to spread rapidly, resulting in a fatal explosion. Thomas died in the incident, while his mother, who was nearby, suffered serious burns as she attempted to rescue her son.
Investigators and prosecutors focused heavily on the facility’s failure to use grounding straps. Such equipment is designed to reduce the risk of static electricity creating sparks, which can be especially dangerous in an oxygen-rich environment.
Prosecutors argued that safety procedures established by industry standards and the chamber manufacturer should have been followed.
Judge Criticizes Failure to Follow Safety Rules
During the sentencing, Oakland County Circuit Judge Kwamé Rowe sharply criticized the decisions surrounding the chamber’s operation.
The prosecution argued that Mosteller, who was responsible for safety at the facility, had a duty to intervene when established precautions were not being followed. His defense acknowledged that he failed to take corrective action but maintained that he never believed his decisions would put Thomas in danger.
Mosteller is the first of four people charged in connection with Thomas Cooper’s death to complete criminal proceedings.
The other defendants include Oxford Center founder and CEO Tamela Peterson, facility management employee Gary Marken and chamber operator Aleta Moffitt. Their cases remain pending, with charges including second-degree murder, involuntary manslaughter and alleged falsification of medical records.
Hyperbaric Therapy Safety Under Scrutiny
The tragedy has also drawn attention to the wider use and regulation of hyperbaric oxygen therapy. The treatment involves placing a patient inside a pressurized chamber and exposing them to high concentrations of oxygen.
The U.S. Food and Drug Administration has cleared hyperbaric oxygen chambers for a limited number of medical conditions. However, the therapy is also used in some settings for conditions outside those established indications, prompting continuing debate about its appropriate use and safety.
Thomas Cooper’s parents have filed a $100 million wrongful-death lawsuit against the clinic and the chamber’s manufacturer. The civil case is separate from the criminal proceedings.
The criminal case against the remaining defendants is still moving through the Michigan courts.
