Fire authorities on Monday conducted a joint state inspection of a gasoline storage tank that exploded and was engulfed in a massive blaze in Goyang, Gyeonggi Province. However, they had yet to determine the exact cause of the explosion, as of Monday evening.

The inspection began at noon and ended in about an hour, faster than the expected three hours, due to the extensive damage to the accident site, according to the police.

The blaze was completely extinguished at 3:48 a.m., some 17 hours after the initial explosion. The fire broke out at a gasoline storage tank in Goyang, Gyeonggi Province, at 10:56 a.m. Saturday.

Based on evidence and data collected at the accident site, the authorities said they would focus on mechanical and chemical factors, to determine the cause of the explosion of the oil storage tank. They also obtained video footage from surveillance cameras installed at the scene. The joint inspection was conducted by the police, the fire department, the National Forensic Service and Korea Gas Safety Corp.

The inspection team added that it would look into safety measures taken right after the fire broke out, as the operator of the storage tank had failed to extinguish the blaze in its first attempt on Sunday.

Some 1.8 million liters of oil were transferred to other storage tanks but 2.6 million liters combusted from the fire, according to the police.

Daehan Oil Pipeline Corp., the operator of South Korea’s oil pipelines, issued an apology Monday and vowed to ensure that a similar accident does not occur.

The facility is believed to have a total of 14 oil tanks, including the one that was engulfed in flames.

The pipeline operator had failed to extinguish the fire in its first attempt. It had turned on automated foam extinguishers to spray some 6,000 liters of foam extinguishing materials for 1 1/2 hours after the fire broke out.

The Daehan corporation said it has not found any factor that could have caused a spark inside the oil tank, and there had not been any kind of external movement or operation outside the tanks when the blaze started.

No one was injured in the blaze.

By Jo He-rim (herim@heraldcorp.com)