Kanagawa Atsugi multi-storey parking lot fire "Is it a flashover phenomenon?"

In August, when more than 8 cars burned in the multi-storey parking lot of a pachinko parlor in Atsugi City, Kanagawa Prefecture, NHK filmed the inside of the parking lot for the first time with the permission of the store. Experts who analyzed the video pointed out that a fire that originated from one car may have caused a phenomenon similar to 'flashover' that spreads to the entire parking lot at once due to the heat of flames and smoke.

On August 8, a fire broke out in the multi-storey parking lot of the pachinko parlor "Maruhan Atsugi Kita" in Atsugi City, and although no one was injured, a total of 20 cars burned, mainly on the second floor.

On the 2th of last month, NHK filmed the interior of the parking lot for the first time with the permission of the store.

The footage was analyzed by several experts, including Mitsutaka Tomita, a researcher at the Forensic Science Appraisal Institute, a private company that conducts fire and accident appraisals.

Of the 152 cars remaining on the second floor, the rubber of the windows and tires was burned, leaving only the steel frame, and the pillars supporting the ceiling were bent, and Tomita analyzed that the site was hot at 11 to 2 degrees.

In addition, when comparing the damage with the drawings of the parking lot at the site obtained through a freedom of information request, it was found that the ceiling was severely damaged downwind from the car that was parked near the center of the parking lot, and the car downwind was burned to the point that the model and color of the car could not be determined.

Tomita points out that the heat of the flames and smoke that reached the ceiling from the car at the source of the fire traveled down the ceiling and spread downwind, and that it may have spread to the entire parking lot at once like a chain reaction of fires caused by the burning of other heated cars.

This means that a fire that occurs in a part of the room seems to be a phenomenon similar to "flashover" that spreads to the entire room in a short period of time.

Researcher Mitsutaka Tomita points out, "Since it is not an enclosed environment like indoors, it is unlikely that the surrounding temperature will become high at once, but this time it is thought that the fire spread because the flames and smoke could not escape to the outside even though the air was passing outdoors."