A large sinkhole near JR Hakata Station in Fukuoka is seen from the sky on Nov. 8. (Video taken by Mahito Kaai)

FUKUOKA--Evacuation warnings were issued and electricity was cut off here after a sinkhole swallowed a huge section of road in front of the largest train station in the Kyushu region on Nov. 8, authorities said.

No injuries were reported in the incident near JR Hakata Station.

The sinkhole was 30 meters long, 30 meters wide and 15 meters deep, but water flowing into the hole from a drain raised the possibility that it could expand further. Police called on people in 10 nearby buildings to leave the area.

The Fukuoka city government acknowledged that work to bore a tunnel for the extension of the Nanakuma subway line caused the cave-in. It apologized for the problem.

Police closed the area to traffic and urged people there not to use open flames after gas temporarily leaked in the neighborhood.

The power supply was disrupted to up to 800 households around the train station.

At around 2:30 p.m., the city government started to fill the hole as a stopgap measure to prevent buildings along the road from collapsing.

Akira Koga, a 25-year-old company employee who lives nearby, saw the sinkhole around 6 a.m.

“I heard an extremely loud noise, so I came here. Then I saw the large hole forming on the road,” he said.

At that time, a traffic light toppled as the hole widened. Sand and dirt continued to fall, and part of the paved road also dropped into the hole, Koga said.

According to the city’s Transportation Bureau, work to dig the tunnel for the subway line was taking place about 25 meters below the five-lane city road in Fukuoka’s Hakata Ward. However, workers took a break around 5 a.m. when groundwater began to flow into the tunnel.

About 10 minutes later, the workers started to check the tunnel while regulating traffic on the road.

The road began to collapse at two sections around 5:15 a.m. Each hole measured 10 meters long and 15 meters wide, but they gradually expanded and eventually connected.

A drilling survey had found that groundwater flowed in areas deeper than 3 to 5 meters below the surface of the ground.

A small amount of water had also seeped into the tunnel during the drilling work. But the volume was within the scope expected, and the fluid was discharged by pumps.

“We had taken thorough steps. But the cave-in, which we feared the most, occurred,” said a high-ranking official of the Transportation Bureau.