The seven to eight meter-wide hole was first reported in the early hours of Tuesday morning local time, according to Motohisa Oda, a crisis management officer from Fukuoka city.
Nearby residents have been evacuated, and five major roads cordoned off in Hakata ward, in Fukuoka city’s busy business district.
The gaping hole — which started off as two smaller holes that merged into one — appeared 300 meters from the JR Hakata railway station.
The sinkhole is now a whopping 27 meters wide, 30 meters long and 15 meters deep. It has also filled with water that seeped in from sewage pipes destroyed by collapsing sections of road
City officials were working nearby to extend the subway from JR Hakata Station to the city center along a 1.4 kilometer route.
Oda told CNN that the hole may have been triggered by the subterranean construction works.
The sinkhole has cut power to roughly 170 households across Fukuoka city. Saibu, a Japan-based gas supplier, is also checking for any gas leakages in the area.
While authorities are still investigating what exactly caused the hole, a few social media users in Japan have been joking about the kind of monsters that might emerge.
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