3 dead during car test at Hyundai Motor plant in Ulsan

Three researchers died of suffocation during vehicle testing at a Hyundai Motor Co. plant in the southeastern city of Ulsan on Tuesday, officials said, Yonhap reports. 

The three -- two Hyundai researchers and the other affiliated with a subcontractor -- were found unconscious at a test chamber where they were conducting a car performance test at around 3 p.m. in the day.

They were taken to nearby hospitals but were pronounced dead, according to company officials and authorities.

The victims were presumed to have been suffocated due to toxic gas in the enclosed space, and a police investigation is under way to find the exact cause of the accident.

Police have also requested autopsies on the bodies to determine the cause of the deaths, they added.

The labor ministry sent labor inspectors to the scene to look into the cause of the accident and to review the applicability of the Serious Accidents Punishment Act.

The act imposes punishment -- at least one year of imprisonment or a fine of up to 1 billion won (US$717,360) -- on business owners or responsible executives for severe industrial accidents that result in death or serious injury.

The automaker expressed condolences to the bereaved families and vowed to actively take necessary measures. It also pledged all-out efforts to prevent a recurrence.