Boy Dies in Hospital Hyperbaric Chamber Fire as Safety Director Is Sent to Prison

A Michigan safety director has been sentenced to prison after a 5-year-old boy died in a devastating fire inside a hyperbaric oxygen chamber while his mother desperately tried to save him.

Thomas Cooper was undergoing treatment at the Oxford Center in Troy, Michigan, on Jan. 31, 2025, when the chamber caught fire and exploded.

The boy had been receiving hyperbaric oxygen therapy for ADHD and sleep apnea, and the fatal treatment was reportedly his 36th session inside one of the devices.

Thomas’ mother, Annie Cooper, tried to intervene as the fire erupted, but she suffered severe burns during the attempted rescue, according to attorneys for the family.

Thomas could not be saved.

Jeffrey Mosteller, who served as the facility’s safety director, later entered a no-contest plea to involuntary manslaughter in connection with the child’s death.

He has now been sentenced to between 19 months and 15 years in prison.

A hyperbaric chamber is a medical device that places patients in a pressurized environment while delivering high concentrations of oxygen. The treatment is used for certain medical conditions, but strict safety procedures are required because of the increased fire risk associated with oxygen-rich environments.

During Mosteller’s sentencing, Oakland County Circuit Court Judge Kwamé Rowe sharply criticized what he described as serious safety failures at the facility.

“This is arrogance,” Rowe said.

A central issue in the case involved grounding straps, which are designed to reduce the risk of static electricity and sparks around the equipment.

Rowe told Mosteller that, as safety director, he had a responsibility to raise concerns about the missing precautions.

“It was incumbent upon you to say something, to say these grounding straps are needed,” the judge said.

Assistant Michigan Attorney General Chris Kessel argued that Mosteller was among those at the center who ignored established safety standards.

Kessel accused the defendants of acting as though they knew more than “doctors and scientists and engineers and safety experts.”

Prosecutors said both the National Fire Protection Association and the chamber’s manufacturer had strict safety rules in place, but claimed those guidelines were not being followed when Thomas died.

Mosteller’s defense team argued that the Oxford Center had already stopped using the grounding straps before Mosteller began working there.

His attorneys nevertheless acknowledged that he failed to correct the problem after taking over safety responsibilities.

“I don’t think for one minute that Jeff thought he was putting Thomas’ life in danger,” one of his attorneys told the court.

The defense also described Mosteller as someone who had developed a close relationship with the boy.

“Jeff had a wonderful rapport with Thomas,” his attorney said. “He cared for him a great deal. You could tell that Thomas was always excited to see Jeff and vice versa.”

Mosteller did not speak before receiving his sentence.

Thomas’ family also chose not to address the court, with prosecutors saying the loss remained too painful for them to discuss publicly.