A fire at a lithium battery factory near Seoul on Monday killed 22 workers, most of them migrant laborers from China, in one of the deadliest blazes in South Korea in years, officials said.
Officials said rescuers were still searching the building in Hwaseong, 28 miles south of Seoul, for one worker who had been reported missing. They said it was unclear whether the worker had been in the building when the fire broke out.
Two workers were hospitalized with serious injuries. Six others suffered minor injuries.
Kim Jin-young, an official with the Hwaseong Fire Department, said 102 people had been working in the factory, owned by the battery maker Aricell, when the fire broke out. The 22 victims included 18 migrants from China and one from Laos, as well as two South Koreans.
They were found dead on the 12,500-square-foot second floor of the factory. The floor had two unlocked exit staircases leading outside, but the workers appeared to have been overcome by the flames and toxic smoke before reaching them, Mr. Kim said.
It took only 15 seconds for the floor to be filled with smoke and flames, said a senior fire official, Jo Seon-ho, during a news briefing Monday.
After trying in vain to put out the blaze with fire extinguishers, he said, the workers rushed to an area of the floor where there was no exit.
The dead migrant workers were temporary hires who were likely unfamiliar with the structure of the building, he said. “The smoke was so toxic you could lose your consciousness after taking one or two breaths,” Mr. Jo said.
Chinese, including ethnic Koreans, are the biggest group of migrant workers in South Korea. Of 523,000 foreigners visiting South Korea on temporary work visas according to government data released late last year, more than 100,000 were from China.
Separately, hundreds of thousands of Korean Chinese are working in South Korea on special longer-term work visas that the country grants to ethnic Koreans living abroad.
After suffering low birthrates for decades, South Korea has become increasingly dependent on migrant workers to fill jobs shunned by locals. Many farms and small factories in industrial towns like Hwaseong could not operate without such migrant workers.
Workers who fled the fire said it started when a single battery cell caught fire, triggering a series of explosions among some of the 35,000 lithium battery cells stored on the factory’s second floor, according to Mr. Kim.
Fires can occur in lithium batteries when the inside layers are compressed, causing a short circuit. The layers can become compressed by a sudden impact, such as during a vehicle collision, or by gradual swelling of the batteries through regular use.
Lithium is a metal that can store large amounts of energy in a small space, which is why it is attractive as a battery material. But that also means there is much energy available to turn into heat and even flames in case of a short circuit. Lithium battery fires have been a growing problem in the United States and elsewhere, and fires are an industrywide concern for battery manufacturers.
Aricell, the Hwaseong plant’s owner, makes batteries that are often used to run electricity and other utilities networks.
Intense flames, toxic smoke and the risk of further explosions hampered firefighters’ efforts to search for the missing workers on Monday. Television footage from the fire showed large flames and thick clouds of smoke billowing from the factory. Footage taken after the fire had been extinguished showed the building scorched, with its roof caved in.
More than 160 firefighters, along with 60 fire engines, rushed to contain the fire. President Yoon Suk Yeol called on his government to “mobilize all available human resources and equipment.”
The blaze was the deadliest in South Korea since a fire at a construction site southeast of Seoul killed 38 people in 2020.
Though South Korea is known for its cutting-edge technology and manufacturing, the country has long been plagued by man-made disasters, including fires.
In 2018, nearly 50 people, most of them elderly patients, died inhaling toxic smoke in a fire at a hospital that lacked sprinklers. In 2017, 29 people were killed in a fire at a gym and public bath complex. In 2008, 40 workers — including migrant workers — died in a fire at a cold-storage warehouse under construction.