3 die from suspected suffocation accident at Hyundai Motor plant in Ulsan

Korean automobile manufacturer Hyundai Motor's Ulsan plant is seen in this photo taken in April 8, 2020. Yonhap

Three people died apparently due to suffocation during vehicle testing at a Hyundai Motor plant in the southeastern city of Ulsan, according to police and officials, Tuesday.

The Ulsan Metropolitan Police Agency said three researchers were found unconscious inside a laboratory at Hyundai Motor's Ulsan Plant 4 complex around 3 p.m. They had been conducting a driving test at the lab.

The three individuals, aged in their 40s, 30s, and 20s, were taken to a hospital in critical condition but were pronounced dead later.

According to a company official, the three individuals did not exit the testing chamber after completing the driving test in the laboratory of Plant 4 around 12:50 p.m. They were later found lying on the floor in the laboratory when others went in to check around 3 p.m.

Hyundai Motor's Ulsan plant is subject to the Serious Accidents Punishment Act with more than 10 full-time workers.

The Ulsan Northern Police Station and the Ministry of Employment and Labor are investigating the exact circumstances of the accident.