The fire on Aug. 1 originated in an unplugged Mercedes-Benz EV parked in the underground garage of an apartment complex. The blaze resulted in 23 people hospitalized for smoke inhalation, while 87 vehicles were destroyed and an additional 783 were damaged.
According to the Incheon Metropolitan Police Agency, the NFS provided a forensic report Thursday indicating the fire likely began in the sedan's underfloor battery pack.
"We cannot rule out the possibility that an external impact to the vehicle's undercarriage damaged the internal cells of the battery pack, leading to insulation failure and ignition," the forensic service was quoted as saying.
However, the forensics team noted that data extraction from the vehicle's battery management system was impossible due to severe damage from the intense combustion during the fire.
The vehicle had been parked for about 59 hours before the fire broke out. Police are investigating the owner's activities prior to parking, as closed-circuit television footage showed no external impacts during that time.
Authorities are also examining the apartment’s fire safety management, as the sprinkler system malfunctioned during the incident.
Earlier, three people, including a night-shift worker at the apartment management office and the fire safety manager, were booked without detention on charges of professional negligence resulting in injury.