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.

Four Michigan medical center workers have been charged in the death of a 5-year-old who was burned alive inside a pressurized oxygen tank that exploded.

Michigan Attorney General Dana Nessel announced charges in connection with death of Thomas Cooper, who died in a hyperbaric chamber explosion.