The on-site joint investigation into the fire accident at S-Oil's Onsan plant, which killed one person and injured nine others, was postponed indefinitely due to concerns about a secondary safety accident.

While S-Oil assumed that a defect in the valve was the cause of the accident, civic groups urged a thorough investigation of the cause and punishment of those responsible.

This is UBC reporter Bae Yoon-ju.


Vehicles of a joint investigation team including the police, Korea Gas Safety Corporation, and the Ministry of Employment and Labor enter S-Oil's Onsan plant one after another.

However, the joint investigation team stopped the investigation without being able to enter the scene of the accident.

This is because of the possibility of additional fires due to residual gas in the pipeline and secondary accidents caused by damaged structures.

As the safety of the alkylation process in which the accident occurred was not secured, the scheduled on-site joint investigation was temporarily postponed.

At a private briefing on the Joint Investigation Team, S-Oil is said to have assumed that the cause of the accident was a defect in some valves in the piping from the LPG raw material tank to the explosion point.

However, civic groups argued that the possibility of human resources could not be ruled out, such as pointing out the possibility that the gas supply device was operated in the control room due to lack of communication between the subcontractor and the contractor during valve maintenance work.

[Making Ulsan Free of Major Accidents Campaign Headquarters: The government thoroughly investigates the cause of this S-Oil explosion, and punishes those in charge of management strictly according to the Severe Disaster Punishment Act!]

In particular, it was criticized that there was no work manager at the main office at the accident site, and there was no space for subcontractor workers to evacuate.

Police said that S-Oil plans to conduct a full-scale on-site investigation after securing safety by completely blocking the gap between the leaking pipes.

(Video coverage: Choi Hak-soon UBC, CG: Song Jeong-geun UBC)