A wastewater storage tank exploded at a South Korean chemical plant on Friday, killing six workers, fire officials have said.
The explosion occurred as workers were welding in a wastewater facility at a chemical plant belonging to Hanwha Chemical in Ulsan, about 300 kilometres southeast of Seoul.
"Gas from the waste water, which had piled up inside the tank, was apparently ignited by the welding torch,” a fire official said.
Nearly 220 emergency workers, government officials and security forces flew to the scene following the accident.
Although the main reason for the explosion isn’t known yet, it is suspected that trapped gas in the facility may have caused the blast, the officials have said.
A formal investigation is underway to determine what caused the incident.