Abstract: At 4:00 p.m. on June 18, 2023, an employee working as a laborer for a dairy farm was in the office. The employee had worked that morning as office manager and needed to use the restroom. For the past two days, the employee had complained to his spouse of not feeling well. The employee went into the restroom and did not come out. A coworker discovered the employee dead hours later. The employee's death was ruled as from cardiac arrest. The next day two coworkers and the infant daughter of one became ill and were treated with hyperbaric oxygen therapy at the hospital due to carbon monoxide poisoning. Later the coroner reported the employee died from a heart attack and carbon monoxide poisoning. The exposure was found to have originated from the calf farm boiler/water heater.