A former safety director at Troy's Oxford Center was sentenced to up to 15 years in prison for the death of a 5-year-old Novi boy.

Oakland County Circuit Court Judge Kwamé Rowe sentenced Jeffrey Mosteller, 66, to 19 months to 15 years Monday, Aug. 31, in Pontiac, The Oakland Press reported. Mosteller is the first person convicted in the Jan. 31, 2025, hyperbaric chamber explosion that killed Thomas Cooper while he was receiving treatment at the facility.

Mosteller pleaded no contest to the involuntary manslaughter charge in July. A second-degree murder charge was dismissed as part of the plea agreement. He received 20 days of jail credit at sentencing.

Prosecutors alleged Mosteller deliberately disregarded safety protocols and ignored precautions published by the National Fire Protection Association (NFPA) and Sechrist, the chamber's manufacturer. The facility did not use grounding straps, which patients wear to prevent static sparks during hyperbaric oxygen therapy, according to WXYZ.

Addressing Mosteller's failure to act on known safety problems at the facility, Judge Rowe said, "It was incumbent upon you to say something."

Defense attorney Alona Sharon acknowledged her client failed to take corrective action. She said the practice of not using grounding straps began before Mosteller started working at the Oxford Center.

Cooper's family was not present at the hearing; the prosecutor said the loss remains too painful for them to address the court. Mosteller, who was present, chose not to speak.

Assistant Michigan Attorney General Chris Kessel, who prosecuted the case, described the consequences in stark terms. He told the court that a 5-year-old boy burned alive while his mother watched.

Three co-defendants still face charges. Tamela Peterson, the Oxford Center's owner and founder, and Gary Marken, a management assistant, are each charged with second-degree murder or, alternatively, involuntary manslaughter, according to the Michigan Attorney General's office. Aleta Moffitt, who was allegedly operating the chamber when it exploded, faces involuntary manslaughter and a charge of placing false information on a chart. No trial dates have been publicly reported for any of the three.

All four defendants are also named in a civil lawsuit filed by the Cooper family. The lawsuit seeks $100 million, WXYZ reported.