FOUR people are facing charges after the death of a 5-year-old boy who was burned alive inside a pressurized oxygen chamber as his horrified mom tried in vain to save him.

The shocking medical accident occurred on January 31, when the chamber exploded into flames during his treatment.

Thomas Cooper, from Royal Oak, Michigan, outside Detroit, was declared dead at the scene after suffering deadly burns.

His mom also sustained serious burns trying to save him, the Associated Press reported.

The incident happened at The Oxford Center in Troy.

“A single spark, it appears, ignited into a fully involved fire that claimed Thomas’s life within seconds,” Michigan Attorney General Dana Nessel said.

Four people, including the facility’s CEO, safety manager, and chamber operator, have now been hit with murder and manslaughter charges.

The center’s founder and chief executive, Tamela Peterson, 58, is facing second-degree murder charges.

Facility manager Gary Marken, 65, and safety manager Gary Mosteller, 64, have also been charged with second-degree murder and involuntary manslaughter.

The chamber operator, Aleta Moffitt, 60, was slapped with involuntary manslaughter and falsifying medical records charges.

Nessel said the spark triggered an inferno inside the hyperbaric chamber, a rare but catastrophic incident.

“Fires inside a hyperbaric chamber are considered a terminal event. Every such fire is almost certainly fatal and this is why many procedures and essential safety practices have been developed to keep a fire from ever occurring,” Nessel said.

Thomas was reportedly undergoing hyperbaric oxygen therapy for sleep apnea and ADHD – treatment the FDA hasn’t approved for these conditions.

Nessel blasted the facility, calling it a “for-profit cash-flow business” that provided unapproved and medically unsupported treatments.

“These treatments were medically unsound and not covered by insurance,” Nessel said.

“This business was a pure cash-flow, for-profit business.”

The Oxford Center did not appear on the accredited facility list of the Undersea and Hyperbaric Medical Society, a list recommended by the FDA.

Investigators said multiple safety lapses were found, including a missing patient grounding strap, no daily maintenance check, and no licensed technician on site.

“The chamber was operating well beyond its service lifetime,” Nessel said.

“This death was entirely preventable.”

NBC News reported that the family’s attorney said the boy had attended multiple sessions before the fatal fire.

Defense attorneys for the accused claimed the tragedy was purely accidental.

“This was a tragic accident and our thoughts and our prayers go out to the family of this little boy. I want to remind everyone that this was an accident, not an intentional act,” Marken’s attorney Raymond Cassar said.

Moffitt’s attorney, Ellen Michaels, said her client is devastated and asked for patience as the legal process unfolds.

The Oxford Center initially expressed shock, saying in a statement that the safety of children has always been a priority.

“Nothing like this has happened in our more than 15 years of providing this type of therapy. We do not know why or how this happened and will participate in all of the investigations that now need to take place,” the center’s statement said.

Hyperbaric therapy delivers concentrated oxygen to patients and is typically approved for conditions like severe burns and non-healing wounds – but not for conditions like ADHD.

The FDA advises patients to only use UHMS-accredited facilities for the treatment.

The Oxford Center’s failure to meet safety standards may have led directly to the boy’s horrifying death, investigators concluded.