[Anchor]Today (11.20), a joint investigation by the police and the Ministry of Employment and Labor was conducted regarding the incident in which three researchers suffocated to death while testing vehicle performance at Hyundai's Ulsan plant.The police are focusing on investigating the CCTV at the accident site to check whether the ventilation system was functioning properly.Kim Ok-cheon reports.[Report]Police and Ministry of Employment and Labor vehicles are entering the Hyundai Ulsan plant one after another.This is part of the joint investigation into the incident where three researchers died while conducting exhaust emission performance tests in a sealed laboratory.[Official from the Ministry of Employment and Labor's Occupational Safety and Health Agency/voice altered: "When checking compliance to workplace safety regulations, work logs or work manuals are important (so we need to investigate)..."]During the six-hour joint investigation, the police confirmed that they checked the overall laboratory facilities where the accident occurred.They are particularly focusing on whether there were any issues with safety facilities, such as exhaust emission equipment.The three deceased researchers were found collapsed in the driver's seat, passenger seat, and back seat of the test vehicle, raising the possibility that the exhaust gases were not discharged outside, leading to the accident.Accordingly, efforts are underway to recreate the experiment conducted at the time of the accident to analyze the exhaust emission levels and risks.[Lee Seong-ki/Team Leader of the Ulsan Police Criminal Mobile Unit 2: "The temperature and humidity (at the time of the accident and now) are different, so we recreated that situation. Inside the chamber..."]Additionally, they are analyzing the CCTV footage from inside the laboratory and the black box of the test vehicle.An autopsy has also been requested to determine the exact time of death.The Ministry of Employment and Labor has ordered Hyundai to halt related operations and has begun special supervision to determine the cause.They are also reviewing the applicability of the Serious Accident Punishment Act.This is KBS News, Kim Ok-cheon.