Thomas Cooper from Royal Oak, Michigan, was pronounced dead at the scene. His mother was standing next to the chamber and suffered injuries to her arms when it exploded Jan. 31 at the Oxford Center in Troy.

Two other people were arrested Monday and also are expected to be arraigned in the child's death, police said.

Three people have been charged with second-degree murder after a 5-year-old boy was killed when a hyperbaric chamber exploded at a medical facility in Michigan earlier this year, officials announced Tuesday.

Allegedly, neither a medical doctor nor a safety supervisor was at the medical facility when the chamber exploded.

The Michigan attorney general has accused the owner of a medical center and three of its employees of ignoring safety standards to make a profit.