Police probe lithium-ion batteries, conflicting accounts in Daejeon data center fire
Police investigating last week’s fire at the National Information Resources Service (NIRS) in Daejeon have identified six lithium-ion batteries believed to have caused the explosion, officials said Monday.
The task force leading the probe retrieved the six batteries from the fifth-floor server room during a joint inspection on Sunday, according to the Daejeon Metropolitan Police Precinct. Investigators identified them among 384 batteries as showing signs of sparking.
Fire authorities removed all the batteries from the server room after extinguishing the blaze and placed them in water tanks to prevent secondary explosions due to residual electricity.
Police plan to send the stabilized batteries to the National Forensic Service (NFS) for detailed analysis.
Police have already questioned seven employees who were at the scene when the accident occurred. The interviews focused on their activities and the sequence of events during the incident. Most said the explosion took place “while workers were moving batteries from the fifth floor to the basement to separate them from the servers.”
All seven are subcontracted workers from a local company, reportedly based in Daejeon, and are certified professionals, police confirmed. Investigators have not yet questioned NIRS employees.
The Ministry of the Interior and Safety and the NIRS previously said 13 people were working at the site at the time, but police said those accounts remain inconsistent. Authorities will verify the number through CCTV footage, work orders and additional witness statements.
Police said no CCTV camera directly captured the explosion, but footage did show sparks and smoke rising shortly after the blast, helping investigators pinpoint the location and identify where the batteries were stored.
Officers are also reviewing statements that “the sparks occurred about 40 minutes after the power was cut off,” a claim made by both workers and NIRS officials. Investigators stressed the need for more “precise verification,” noting that the cause could differ depending on whether the fire resulted from a battery explosion or other electrical factors.
Authorities will also look into whether the workers followed safety procedures during the battery transfer. The presence of a supervisor on-site will be a key focus, as violations could lead to charges under the Occupational Safety and Health Act.
A police official said,
Tools collected from the site during the three rounds of inspections have been sent to the NFS for analysis,
“We will determine the exact cause of the explosion through battery examinations and further questioning of workers.”
This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom.
READ the latest Batteries News shaping the battery market
Police probe lithium-ion batteries, conflicting accounts in Daejeon data center fire, source
