Topline: A Troy clinic safety manager pleaded no contest after prosecutors said the oxygen chamber that killed 5-year-old Thomas Cooper was operated in defiance of basic safety standards.
Published: July 23, 2026 10:04 pm ET
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TROY, MI — The safety manager at the Oxford Center in Troy pleaded no contest Tuesday to involuntary manslaughter in the death of 5-year-old Thomas Cooper, who was killed when a hyperbaric oxygen chamber exploded during treatment in January 2025.
According to The Associated Press and a July 21 release from Michigan Attorney General Dana Nessel, Jeffrey Mosteller entered the plea under an agreement calling for a sentence of 19 months to 15 years in prison, while a second-degree murder charge was dropped.
Thomas Cooper died on Jan. 31, 2025, when the chamber he was inside at the Oxford Center caught fire from the inside and exploded. His mother, who was standing nearby, was injured in the blast.
Prosecutors said the clinic operated the chamber beyond its expected service life and ignored safety rules published by both the manufacturer and the National Fire Protection Association. Prior reporting and court testimony cited by ClickOnDetroit said alleged violations included failing to use grounding wrist straps, giving the child a blanket taken directly from a dryer, and tampering with the chamber’s cycle history. A judge earlier noted that employee safety concerns appeared to have been ignored.
Nessel said Mosteller allowed an outdated device to keep operating in defiance of safety standards, calling the child’s death a preventable tragedy. The Oxford Center had promoted hyperbaric oxygen therapy for conditions including autism, ADHD, and autoimmune diseases, though the FDA recognizes the treatment as safe and effective only for a limited list of conditions such as severe burns, decompression sickness, and certain wounds.
Mosteller is the first of four defendants in the case to take a plea. Three other people, including Oxford Center CEO Tamela Peterson, are still awaiting trial, and the Cooper family has also filed a $100 million wrongful death lawsuit.
Mosteller is scheduled to be sentenced Aug. 31 before Oakland County Circuit Judge Kwame Rowe.
Presumption of Innocence: A presumption of innocence means that any defendant in a criminal trial is presumed to be innocent until they have been proven guilty beyond a reasonable doubt in a court of law. The defendant in this case is only accused of the charges set forth in the criminal complaint. They are innocent until proven guilty.
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Safety Manager Pleads No Contest to Manslaughter After 5-Year-Old Killed in Troy Hyperbaric Chamber Explosion
A Troy clinic safety manager pleaded no contest after prosecutors said the oxygen chamber that killed 5-year-old Thomas Cooper was operated in defiance of basic safety standards.
By Silvia Torres
Published: July 23, 2026 10:04 pm ET
TROY, MI — The safety manager at the Oxford Center in Troy pleaded no contest Tuesday to involuntary manslaughter in the death of 5-year-old Thomas Cooper, who was killed when a hyperbaric oxygen chamber exploded during treatment in January 2025.
According to The Associated Press and a July 21 release from Michigan Attorney General Dana Nessel, Jeffrey Mosteller entered the plea under an agreement calling for a sentence of 19 months to 15 years in prison, while a second-degree murder charge was dropped.
Thomas Cooper died on Jan. 31, 2025, when the chamber he was inside at the Oxford Center caught fire from the inside and exploded. His mother, who was standing nearby, was injured in the blast.
Prosecutors said the clinic operated the chamber beyond its expected service life and ignored safety rules published by both the manufacturer and the National Fire Protection Association. Prior reporting and court testimony cited by ClickOnDetroit said alleged violations included failing to use grounding wrist straps, giving the child a blanket taken directly from a dryer, and tampering with the chamber’s cycle history. A judge earlier noted that employee safety concerns appeared to have been ignored.
Nessel said Mosteller allowed an outdated device to keep operating in defiance of safety standards, calling the child’s death a preventable tragedy. The Oxford Center had promoted hyperbaric oxygen therapy for conditions including autism, ADHD, and autoimmune diseases, though the FDA recognizes the treatment as safe and effective only for a limited list of conditions such as severe burns, decompression sickness, and certain wounds.
Mosteller is the first of four defendants in the case to take a plea. Three other people, including Oxford Center CEO Tamela Peterson, are still awaiting trial, and the Cooper family has also filed a $100 million wrongful death lawsuit.
Mosteller is scheduled to be sentenced Aug. 31 before Oakland County Circuit Judge Kwame Rowe.
Presumption of Innocence: A presumption of innocence means that any defendant in a criminal trial is presumed to be innocent until they have been proven guilty beyond a reasonable doubt in a court of law. The defendant in this case is only accused of the charges set forth in the criminal complaint. They are innocent until proven guilty.
Editor's Note: ThePo makes every effort to accurately transcribe the contents of affidavits of probable cause contained in criminal complaints. Often, the complaints themselves are copies of copies of faxed copies, and are difficult to read. To confirm the accuracy of our transcription, contact the Magisterial District Court listed above and request a copy of the criminal complaint. It's a public record to which you are entitled.
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Safety Manager Pleads No Contest to Manslaughter After 5-Year-Old Killed in Troy Hyperbaric Chamber Explosion
A Troy clinic safety manager pleaded no contest after prosecutors said the oxygen chamber that killed 5-year-old Thomas Cooper was operated in defiance of basic safety standards.
By Silvia Torres
Published: July 23, 2026 10:04 pm ET
TROY, MI — The safety manager at the Oxford Center in Troy pleaded no contest Tuesday to involuntary manslaughter in the death of 5-year-old Thomas Cooper, who was killed when a hyperbaric oxygen chamber exploded during treatment in January 2025.
According to The Associated Press and a July 21 release from Michigan Attorney General Dana Nessel, Jeffrey Mosteller entered the plea under an agreement calling for a sentence of 19 months to 15 years in prison, while a second-degree murder charge was dropped.
Thomas Cooper died on Jan. 31, 2025, when the chamber he was inside at the Oxford Center caught fire from the inside and exploded. His mother, who was standing nearby, was injured in the blast.
Prosecutors said the clinic operated the chamber beyond its expected service life and ignored safety rules published by both the manufacturer and the National Fire Protection Association. Prior reporting and court testimony cited by ClickOnDetroit said alleged violations included failing to use grounding wrist straps, giving the child a blanket taken directly from a dryer, and tampering with the chamber’s cycle history. A judge earlier noted that employee safety concerns appeared to have been ignored.
Nessel said Mosteller allowed an outdated device to keep operating in defiance of safety standards, calling the child’s death a preventable tragedy. The Oxford Center had promoted hyperbaric oxygen therapy for conditions including autism, ADHD, and autoimmune diseases, though the FDA recognizes the treatment as safe and effective only for a limited list of conditions such as severe burns, decompression sickness, and certain wounds.
Mosteller is the first of four defendants in the case to take a plea. Three other people, including Oxford Center CEO Tamela Peterson, are still awaiting trial, and the Cooper family has also filed a $100 million wrongful death lawsuit.
Mosteller is scheduled to be sentenced Aug. 31 before Oakland County Circuit Judge Kwame Rowe.
Presumption of Innocence: A presumption of innocence means that any defendant in a criminal trial is presumed to be innocent until they have been proven guilty beyond a reasonable doubt in a court of law. The defendant in this case is only accused of the charges set forth in the criminal complaint. They are innocent until proven guilty.
Editor's Note: ThePo makes every effort to accurately transcribe the contents of affidavits of probable cause contained in criminal complaints. Often, the complaints themselves are copies of copies of faxed copies, and are difficult to read. To confirm the accuracy of our transcription, contact the Magisterial District Court listed above and request a copy of the criminal complaint. It's a public record to which you are entitled.
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