TROY, Mich. (WWJ) - Four people were arrested in a case tied to the death of a 5-year-old boy in a hyperbaric chamber explosion in Michigan. Investigators say 5-year-old Thomas Cooper was in the chamber Jan. 31 when it exploded at the Oxford Medical Center in Troy, Michigan. His mother, who was in the room at the time, was also injured.

Michigan Attorney General Dana Nessel has charged four people in connection with the death of a 5-year-old boy who was killed in a hyperbaric chamber explosion.

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.