S-Oil Chief Executive Officer Hussain A. Al-Qahtani on Friday apologized over the explosion of its refinery in Ulsan, about 415 kilometers southwest of Seoul, and promised to take all measures possible to prevent such incident from happening again.

“I would like to express my deepest condolences and apologies to the deceased who lost his life from an incident in S-Oil Onsan Refinery and to his family. My apologies also go out to the injured workers and local residents close to the refinery to whom we’ve caused discomfort,” the CEO said during a press conference in Ulsan.

“I, myself and S-Oil will provide full support to make sure the injured workers get the best treatment possible and give utmost care to assist their quick recovery.”

The explosion took place in the refinery’s Alkylation unit at approximately 8:50 p.m. on Thursday, killing one person and injuring nine others.

It is presumed that a fire was ignited in the compressor during the start-up process after maintenance, according to S-Oil and firefighters.

Firefighters successfully extinguished the fire at around 12 p.m. Friday, 15 hours after the explosion took place.

“The affected plant will be shut down until the root cause is identified and preventive measures are put in place. In the meantime, we are exploring the best solutions to make sure this does not cause any interruption in domestic supply of fuel products by making full use of inventory and domestic or overseas network,” the CEO added.