A large sinkhole appeared in Saitama Prefecture last week, swallowing a truck along with its 74-year-old driver.
Rescuer workers were immediately dispatched to the area. They initially heard the driver’s calls for help but soon lost contact. In efforts to rescue the man, they tried lifting part of the truck out of the pit using cranes and also sent drones.
However, the rescue efforts were suspended after a few days as further cave-ins made the ground around the pit unstable. Rescuers now plan to reach the driver using a 30-meter slope that was constructed to send down heavy equipment.
Since then, the hole has expanded considerably—it is now over 40 meters wide, approximately four times its original width. Officials say it continues to grow each day.
Local authorities are asking 1.2 million local residents to refrain from doing laundry and bathing to cut down on wastewater, which could further complicate the rescue mission.
Pipe Decay
Authorities believe the sinkhole opened due to corroded sewer pipes that caused the earth to fall in. Wastewater may have also leaked in, further eroding the surrounding area, widening the pit.
According to the United States Geological Survey, sinkholes are commonly seen in areas underlain by rocks such as limestone or gypsum, which can be dissolved by groundwater.
Takashi Oguchi, a geographer who works at the University of Tokyo, said sinkholes are rare in Japan as most roads are built on marine or fluvial sediments. However, they can appear if large underground pipes rupture, causing wastewater to wash away the sediments.
Most of the public infrastructure in Japan was built between the ’50s and ’60s during an economic boom following World War II.
The sewage system associated with the recent sinkhole was built 42 years ago.
Oguchi said there will likely be ‘more events in the future’ due to the decay of underground pipes. Many are also located below roads, which complicates the situation.
Inspecting them is also a challenge as they are buried deep underground.
Rescue Operation Has Been Difficult
For days, rescuers raced to save the 74-year-old man who is trapped meters below ground.
However, the mission has proven to be challenging, especially after the original sinkhole merged with a second hole, causing it to expand.
A Sewerage Works Division official said the man was ‘buried in earth and sand’ but they could not bring heavy equipment near the area as it could fall in.
They decided to build a slope instead so they could bring heavy machinery into the sinkhole. It was completed on Saturday morning but the rescue operation had to be halted after wastewater gushed out near the end of the slope.
Officials have since begun creating a second slope from a different angle. It is expected to reach closer to where the man fell in.
