A former safety manager lost his freedom after a Michigan judge sent Jeffrey Mosteller to prison for one year and seven months following the death of five-year-old Thomas Cooper. Mosteller, 66, pleaded no contest to involuntary manslaughter in Oakland County circuit court and was sentenced on Monday.
Mosteller had worked as the safety manager at the Oxford Center, a Troy facility that offers hyperbaric oxygen therapy to children for conditions including autism, attention deficit hyperactivity disorder and autoimmune diseases. The child, from Royal Oak, was receiving treatment for ADHD and sleep apnea when a fire erupted inside the pressurised chamber in January 2025. The blast killed the boy.
An expert who reviewed video evidence concluded the child had disturbed bedding inside the tank, which created a static spark. In the oxygen-rich chamber that spark became a flash fire, and the child was fatally burned within seconds. Thomas’s mother suffered severe burns to her arms and chest while trying to open the unit.
Mosteller is one of four former Oxford Center employees charged over the incident. Three others remain awaiting trial: founder and chief executive Tamela Peterson, 58, faces a charge of second-degree murder; facility manager Gary Marken, 65, is charged with second-degree murder and involuntary manslaughter; and operator Aleta Moffitt, 60, is charged with involuntary manslaughter and allegedly falsifying medical chart entries.
Thomas’s parents have filed a $100m wrongful death lawsuit against the clinic and the manufacturer of the chamber. The case has revived scrutiny of hyperbaric oxygen therapy, which the US Food and Drug Administration has authorised for marketing as safe and effective for 13 disorders, including severe burns, decompression sickness and non-healing wounds. The treatment works by delivering pure oxygen inside a pressurised chamber.
The therapy’s growing use has drawn controversy, with some public figures and their allies promoting wider application and others warning against expanding its mainstream role without stronger safety oversight. Criminal trials for the remaining defendants and the civil lawsuit will determine the next legal steps in the case.
