Aeon Mall Kumamoto, the biggest shopping mall in Japan's Kumamoto prefecture that collapsed in an earthquake 10 years ago and reopened under the banner of being a "disaster-resilient facility," crumpled again 45 days after its reopening.
At 4:27 p.m. on the 28th, a magnitude 7.1 earthquake struck Kumamoto prefecture in Japan, and within 30 minutes of the quake, a massive explosion ripped through the entire Aeon Mall Kumamoto. The blast was strong enough to tear off the entire second-floor slab and the exterior wall. Aeon Mall ushered consumers out of the building immediately after the quake.
But the explosion trapped dozens of employees who had remained inside. In the early hours of the 29th, after an overnight rescue operation, authorities confirmed that two women who appeared to be in their 20s had died, but the cause of the explosion has not yet been determined.
Aeon Mall Kumamoto, where the explosion occurred, is the largest commercial facility in Kumamoto prefecture, with about 200 specialty stores and a movie theater. Major Japanese media said the mall draws more than 8 million visitors annually. The mall sits in Kashima-machi, a small town on the southeastern outskirts adjacent to Kumamoto city. It pulls in the entire southern Kumamoto consumer base, and in Korea it would be akin to a large mixed-use mall on a city's outskirts that attracts a wide regional customer base.
Aeon Mall Kumamoto also faced an earthquake at the same site 10 years ago. On Apr. 14 and 16, 2016, two intensity 7 quakes swept through Kumamoto two days apart, forcing the complete closure of the mall's western specialty-store zone. It then took nearly a year just to restore it. On Mar. 24 the following year, Aeon Mall resumed operations at 49 stores in the western zone and restarted normal operations as before. At that time, it also carried out a remodeling that brought in 16 new stores, including the large theater Aeon Cinema Kumamoto.
Afterward, Aeon Mall promoted a "more disaster-resilient mall" and carried out various reinforcement works. Aeon Mall said that along with several reinforcement projects at the time, it made the ceiling earthquake-resistant and completely reexamined the installation positions and methods of lighting fixtures and equipment that hung from the ceiling. On the 13th of last month, Aeon Kumamoto, the mall's anchor store and its most visited hypermarket, completed a major remodeling that overhauled most of the sales floor and reopened. Major Japanese media reported that Aeon Kumamoto revamped its food and cosmetics sections and even added beauty appliances and game experience corners to appeal across generations, but a magnitude 7.1 earthquake hit 45 days later.
The Kumamoto prefectural disaster response headquarters said that by 4 a.m. on the 29th, it had rescued eight people from Aeon Mall, and among them, two women who appeared to be in their 20s had died and one woman was in cardiopulmonary arrest. NHK reported that the majority of the 20 to 30 people unaccounted for as of early on the 29th were employees of tenant shops and mall operations staff. FNN reported, "The explosion damage was concentrated on the south side of the mall, where variety and clothing stores are located, and there was a food court on the second floor."
NHK added that before the explosion there was a tip that gas was leaking inside the building at Aeon Mall. Nippon TV said Japanese fire authorities are looking into the possibility of a gas explosion. However, it has not been confirmed whether piping and equipment broke first in the quake, what ignition source contacted the leaked gas, or how far the blast pressure widened the collapse.
Experts said that even buildings with completed seismic retrofitting cannot entirely avoid earthquake damage. Seismic design focuses on helping a building hold up amid shaking to buy time for people to evacuate. Even if the structural frame endures, nonstructural elements such as ceiling materials and exterior wall panels can fall and worsen the damage. If gas or electrical lines are severed, the risk of explosions and fires like this one surges. The items Aeon Mall overhauled on a large scale starting in 2017 after the previous quake damage were also concentrated mainly on ceilings and equipment.
Kumamoto prefectural police and fire authorities said they will investigate whether the explosion started from equipment damaged by the quake and how far the blast expanded the building's collapse.