It has been revealed that the core tactic used by the fire authorities to extinguish the fire at the Incheon Coupang logistics center—which had even raised concerns about a potential collapse—without major casualties was none other than water vapor.

According to the Incheon Fire Headquarters yesterday (July 22), when a fire broke out at the Coupang 32 Logistics Center—an 8-story building above ground with a total floor area of 299,000 square meters—at 6:54 AM on the 18th, the fire authorities chose water vapor as their tactic to combat the flames.

Named the "ventilation control and water vapor suffocation/cooling tactic," this approach was adopted to achieve two goals: ensuring the safety of firefighters and preventing the spread of the fire.

The core of this tactic utilizes the principle that when discharged water absorbs high heat and turns into water vapor, its volume expands by approximately 1,700 times.

As the water vapor expands, the oxygen concentration inside the logistics center drops sharply, which can lower the intensity of the flames.

Furthermore, the powerful heat-absorption effect generated during the process of water turning into vapor prevents the explosive spread of fire inside the warehouse and maintains a low-temperature combustion (smoldering) state.

Following this tactic, the fire authorities intensively sprayed water using high-reach ladder trucks, articulated trucks, and helicopters into open spaces (openings), including ventilation ports on the outer walls of the logistics center and gaps in the damaged exterior walls.

At the time, high-reach ladder and articulated trucks that arrived one after another at the fire scene under the National Fire Mobilization Order—which mobilized personnel and equipment from 8 neighboring cities and provinces—became the core equipment for this strategy.

As the fire authorities' core tactic took effect, the fire, which had spread from the 6th to the 7th floor of the logistics center, fortunately did not spread to the 5th floor, where hundreds of robots equipped with lithium batteries (equivalent to 20 electric vehicles) were located.

Had the fire spread to the 5th floor, the "thermal runaway phenomenon" caused by the combustion of lithium batteries could have affected the nearby SK Incheon Petrochem plant.

By preventing the spread of the fire without directly deploying firefighters into the 6th and 7th floors of the logistics center, the fire authorities also prevented any additional casualties.

Aside from two firefighters who received hospital treatment for smoke inhalation and exhaustion, respectively, no other casualties resulted from this fire.