The incident happened at an LG display factory in Paju which is 40 km north of Seoul, South Korea. The victims were doing their regular repair and maintenance routine at a few minutes past noontime when the nitrogen leak occurred.

One of the victims died on the spot while another was pronounced dead before arriving at the hospital. Four more victims were affected by the leak wherein one is in serious condition. All of the victims in the incident are in their 30s.

The factory in the South Korean city of Paju is where the company manufactures liquid crystal displays for their products. One of them is the LCD screen for large TV sets. It is believed that the factory is where the world's largest production of OLED TVs and display panels for LCD takes place.

Nitrogen makes up almost 80 percent of the atmosphere. It is a colorless and odorless substance which makes it very difficult to detect. When nitrogen gas is released rapidly into an enclosed space, it displaces oxygen and poses an asphyxiation threat. Such threat may happen in the midst of few warning symptoms. This is because the human carotid body has a low-oxygen sensing system that is relatively slow and poor.

In the factory where the incident occurred, nitrogen is used to wash the display screens while they are manufactured.

LG expressed deep regret over the deaths and promised that it will cooperate with the authorities in their investigation on the cause of the leak. There were over a dozen firefighters that were deployed in the area in order to make sure that no other fatal accidents would occur.

LG offered an apology to the victims and their families shortly after the tragedy.

"We send our most heartfelt condolences and apologies to the deceased and will do everything in our power to help the injured recover as quickly as possible," said the company in a statement.

The incident on Monday followed a similar nitrogen leak which occurred in late last month. The incident, which took place at the Shingori 3 nuclear reactor in Ulsan, South Korea, left at least three workers dead.