The explosion that occurred on the 1st at the Hanwha Aerospace Daejeon plant is believed to have happened during cleaning work related to explosives. Five people were killed, and two sustained serious injuries.

According to police and fire authorities, at 10:59 a.m. that day, a fire also broke out due to the explosion at the Hanwha Aerospace Daejeon site in Oesam-dong, Yuseong-gu, Daejeon. In response, at 11:17 a.m. the fire authorities issued Response Level 1 and began firefighting operations, and the blaze was fully extinguished at 1:07 p.m., 1 hour and 50 minutes later. The fire completely destroyed a one-story building with a floor area of 544㎡.

According to Hanwha Aerospace, the explosion occurred in the 'Building 56 cleaning room' at the Daejeon site. What was being cleaned at the time of the explosion has not been confirmed. Because this site is a national security facility, details such as the work process and the layout of the workplace are not disclosed. A company representative said only, "It is presumed that an explosion of unknown cause occurred during a cleaning operation involving explosives."

There were nine people at the scene, and two reportedly evacuated. The five who died were found inside the work area, and one of the two injured is in critical condition with full-body burns. The other is believed to have sustained minor burns. The police stated, "We have contacted the National Forensic Service to identify the deceased."

Hanwha Aerospace is a defense company that manufactures aircraft engines, space launch vehicle engines, weapons, and shells. The Daejeon plant has previously had two explosions. In May 2018, two people were killed in an explosion, and three who suffered severe burns later died while receiving hospital treatment. In February 2019, an explosion and fire occurred in the propellant molding room of Building 70 at the Daejeon plant, killing three workers.

Hanwha Group and Hanwha Aerospace issued a statement the same day, saying, "We pray for the repose of the employees who lost their lives and extend our deepest condolences to their bereaved families," and, "We will spare no effort to support the treatment of employees injured in the accident." They added, "Hanwha Group will thoroughly determine the cause of the accident to ensure such a tragic accident never happens again," and, "We bow our heads in apology to the public."