Abstract: At approximately 8:12 a.m. on June 2, 2011, Employee #1 was working for Southwest Airlines, loading bags at Gate 23 at San Francisco International Airport, in San Francisco, CA. In an interview, Employee #1 stated that the morning of June 2, 2011, was a normal morning. Employee #1 said he took a break while waiting for an aircraft to arrive. Upon arrival of the aircraft, Employee #1 and his coworkers unloaded bags from the airplane. They then continued their work, by loading bags onto the airplane. Employee #1 was in the forward bin of the aircraft stacking bags, while a coworker was on the ramp placing bags on the belt loader. According to Employee #1, he did not feel any pain, weakness, or any other symptom while he was working. Employee #1 said he was sweating, which was normal for him when he loaded and unloaded bags. Employee #1 said he was diabetic and that he controlled his diabetes with insulin treatment. Employee #1 did not recall collapsing or falling on the floor. Employee #1's coworker, a ramp agent who saw Employee #1 on the floor of the aircraft bin, was interviewed. He stated that, when he noticed that the bags on the belt loader were backed up, he went to check on Employee #1, whose assignment was to stack bags in the forward bin of the aircraft. The ramp agent found Employee #1 on the floor of the bin, unconscious and unresponsive. Employee #2 immediately made a call to notify his supervisor of the emergency situation. The ramp agent rendered CPR by applying chest compressions on Employee #1. When the supervisor arrived, he took over applying chest compressions on Employee #1. The ramp agent went to the aircraft cabin and requested assistance from the flight attendants. They brought with them an automated external defibrillator (AED), which they used on Employee #1. Emergency responders arrived, and Employee #1 was taken to Peninsula Hospital for treatment of ventricular fibrillation and cardiac arrest, and for a thorough examination. Employee #1 had sustained a cardiac arrest. On June 4, 2011, Employee #1 was discharged from Peninsula Hospital and was transferred to the Kaiser Permanente San Francisco Medical Center. Employee #1's cardiac catheterization at Kaiser Permanente showed multi-vessel disease, and he was referred for cardiovascular surgery. Employee #1 underwent coronary artery bypass surgery at the Kaiser Permanente San Francisco Medical Center and was discharged on June 13, 2011. The investigation concluded that the cardiac arrest sustained by Employee #1 was not work-related. No citation was issued to the employer.