Ex-Safety Manager Sentenced to 19 Months for Boy's Hyperbaric Chamber Death

Jeffrey Mosteller, a 66-year-old former safety manager, was sentenced to one year and seven months in prison on Monday in Oakland County Circuit Court, Michigan. This sentence stems from the death of five-year-old Thomas Cooper, who perished in a fiery explosion inside a hyperbaric oxygen chamber in January 2025. Mosteller pleaded no contest to a charge of involuntary manslaughter in relation to the incident. The plea signifies that Mosteller does not admit guilt but accepts the conviction and punishment.

The tragic event occurred when the hyperbaric chamber, a medical device used to deliver oxygen at higher than atmospheric pressure, ignited. Hyperbaric oxygen therapy is often employed to treat conditions such as decompression sickness, carbon monoxide poisoning, and certain infections. However, the use of pure oxygen in a pressurized environment can create a significant fire risk if not managed with extreme caution and adherence to strict safety protocols. The investigation into the explosion likely focused on the safety procedures in place at the time and the role Mosteller, as safety manager, played in overseeing these procedures. The specific details of how the fire started within the chamber have not been fully elaborated in the provided information but are central to the involuntary manslaughter charge.

Involuntary manslaughter is a legal charge that typically involves causing someone's death through recklessness or criminal negligence, without the intent to kill. In this context, the prosecution would have needed to demonstrate that Mosteller's actions or omissions, as safety manager, fell below the standard of care expected and directly contributed to the fatal outcome for Thomas Cooper. The plea of no contest means Mosteller will be treated as if he were convicted of the charge, avoiding a full trial but acknowledging the court's jurisdiction to impose a sentence. The sentencing on Monday marks a significant legal development in the case, bringing a measure of closure to the victim's family, though the profound loss of a child remains.

The case highlights the critical importance of stringent safety regulations and oversight in environments where specialized medical equipment, particularly that involving high concentrations of oxygen, is utilized. The death of Thomas Cooper serves as a somber reminder of the potential dangers associated with medical treatments when safety protocols are compromised. The legal proceedings against Mosteller underscore the accountability expected from individuals in positions of safety management within healthcare or any industry where hazardous conditions may exist. The sentence of 19 months in prison is intended to reflect the severity of the negligence that led to the child's death.