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.

The CEO of a therapy treatment center was among three employees charged with second degree murder and involuntary manslaughter after a young boy burned to death inside a hyperbaric oxygen chamber in Troy,

Dana Nessel will be announcing the arraignment for Tammi Peterson for second-degree murder and manslaughter charges. She is the center's founder and CEO, which owned and operated the chamber.

The boy, Thomas Cooper, was “incinerated” inside a pressurized oxygen chamber that exploded at Oxford Center, a medical facility in a Detroit suburb, on Jan. 31. His mother was standing next to the chamber and was injured trying to save her boy.

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.

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

Tamela Peterson, founder and CEO of The Oxford Center, will be arraigned, along with Jeff Mosteller, the center's safety director, according to records.