Multiple fires were reported at Posco’s steel plant in southeastern city of Pohang, Gyeongsang Province, Tuesday morning, but the company said the picture showing dark smoke surrounding its facilities that went viral online was not due to fire but the release of byproduct gas at the plant caused by a power outage. The outage was due to Typhoon Hinnamnor that was passing by the peninsula earlier in the morning, Posco official said, adding that the company is investigating if the typhoon had also caused fires at plants.

According to news reports, fires broke out at Posco's second steelmaking factory and the second hot rolling plant at 7:17 a.m. Both were put out immediately without any casualties, Posco said, adding that they are still looking into the cause and assessing the damage. A total of 22 employees who were isolated at the flooded site due to heavy rain on Monday were all safely rescued.

The release of gas that was supposed to be burned inside the plant, but accidentally exposed outside the plant was due to an error in the fan caused by the power outage, it added

Meanwhile, another fire also broke out at Hyundai Steel’s Incheon plant in the morning, at around 6:30 a.m.

The company and the Incheon Fire Department said the Energy Storage System (ESS) located in the first floor of the plant caught on fire, leaving no casualties.

An ESS is used for charging batteries overnight. Due to its complicated structure and toxic gases released from batteries when on fire, it was difficult to extinguish the fire, according to the fire authorities, who also issued a "second stage response" at around 7:30 a.m and dispatched 183 fire fighters to the scene.

The company said the ESS that caught on fire is owned by a local bank and Hyundai Steel borrows part of the energy generated through the system. Officials said they are still assessing the cause and damage.

(ddd@heraldcorp.com)