Japan is on the seismically active “ring of fire” around the Pacific Ocean and has building codes aimed at helping structures withstand earthquakes.

The epicenter of Saturday’s quake was near the city of Kumamoto and measured at a shallow depth of six miles, the United States Geological Survey USGS said. The shallower a quake, the more likely it is to cause damage.

The quake triggered a tsunami advisory which was later lifted and no irregularities were reported at three nuclear power plants in the area, a senior government official said.

The city’s 400-year-old Kumamoto Castle was badly damaged, with its walls breached after having withstood bombardment and fire in its four centuries of existence.

Local residents look at cracks caused by an earthquake on a road in Mashiki town, Kumamoto prefecture, southern Japan,  April 16, 2016. Mandatory credit REUTERS/Kyodo

The USGS, which is a government scientific body, estimated that there was a 72 percent likelihood of economic damage exceeding $10 billion, adding that it was too early to be specific. Major insurers are yet to release estimates.

Electronics giant Sony Corp said a factory producing image sensors for smartphone makers would remain closed while it assessed the damage from the quakes. One of its major customers is Apple which uses the sensors in iPhones.

Toyota Motor Corp halted production at three plants producing vehicles, engines and trans axles in Fukuoka. Toyota said there was no damage at its plants, but it was checking the status of its suppliers. It will decide on Sunday whether to resume production.

Nissan Motor Co Ltd stopped production at its Fukuoka plant which produces vehicles including the Serena, Teana, Murano and Note.

South Korea said it had rented five buses to transport 200 South Korean tourists stranded in Oita, to the east of Kumamoto.

Chief Cabinet Secretary Yoshihide Suga said nearly 80 people were believed trapped or buried in rubble. Rescuers managed to pull 10 students out of a collapsed university apartment in the town of Minami on Saturday.

Extra troops would be sent to help, with up to 20,000 due by Sunday, as well as more police, firefighters and medics, he said. “We are making every effort to respond,” Suga said.

The region’s transport network suffered considerable damage with one tunnel caved in, a highway bridge damaged, roads cut or blocked by landslips and train services halted, media reported. Kumamoto airport was also closed.

There have been more than 230 aftershocks of at least level 1 on the Japanese scale since Thursday’s shock, said Japan‘s meteorological agency.

“We have already seen of several of the mid to upper 5 plus magnitude range, and over the next several days and weeks, we would not be surprised to see more earthquakes of this size,” said John Bellini, a geophysicist with the USGS.

Source: HuffPost