New details revealed in Troy hyperbaric chamber explosion case that killed 5-year-old

TROY, Mich. (FOX 2) - On the first day of the preliminary hearing back in September, a former employee revealed unsafe practices at a Troy medical facility that potentially led to the death of a child in January.

On Monday, an expert in hyperbaric chambers took the stand discussing the details of what happened.

Big picture view:

In January 2025, a hyperbaric chamber at the Oxford Center in Troy exploded, killing 5-year-old Thomas Cooper, who was inside. His mother was injured as well.

Since then, four people have been charged:

• CEO and founder Tamela Peterson Assistant Gary Marken, and safety manager Jeffery Mosteller have been charged with second-degree murder and involuntary manslaughter.
• Chamber operator Aleta Moffit has been charged with involuntary manslaughter and intentionally placing false information on medical records.

In September, the preliminary hearing began with former employee Tiffany Hosey testifying about alerting the center to unsafe practices, specifically that patients were not being strapped in.

What they're saying:

On Monday, hyperbaric safety expert Andrew Melnyczenko took the stand. He shared his observations after reviewing video footage of Cooper's movements in the chamber and the incident.

Attorney: "Did it appear to you that Thomas was wearing a grounding strap at the time the fire started?"

Melnyczenko: "It did not."

Attorney: "And, let me ask you this. Did you watch the entire video, not just the end of it but the entire video?"

Melnyczenko: "We spent the better part of the day with the Troy Police Department reviewing bits of the video. We did watch the video in its entirety in the morning, as far as the two videos you're referring to. You're referring to one that shows the operator's panel of chamber No. 2, and the second video we watched was an overhead view that faced all three chambers."

Melnyczenko: "Because the patient was not grounded continuously with skin contact on the wrist strap, the only thing that could have potentially grounded him was the grounded mattress. So, if he had built up static and then came into contact with a grounded surface, that increases the potential for a static discharge to occur."

What's next:

On Monday in court, there was also some back-and-forth about pillows, with Melnyczenko expressing concern about the polyester filling. The defendants' attorneys objected, saying it was irrelevant.