Emergency workers are struggling to rescue a truck driver who was swallowed by a sinkhole more than two days ago in a city just north of Tokyo.

The 74-year-old man had stopped near an intersection in Saitama Prefecture when the sinkhole suddenly opened beneath the road, swallowing him with the truck, according to a witness interviewed by local media.

The driver was alive immediately after the truck sank into the hole, responding to nearby rescuers, according to the public broadcaster NHK. However, a few hours later, a mudslide inside the hole caused dirt and rubble to fall onto the vehicle, burying it. The man has not responded to subsequent attempts to make contact.

Rescue efforts have been complicated by the fragility of the ground around the hole. A second hole that emerged nearby on Tuesday merged with the first one early Thursday, forming a larger sinkhole. The collapsed area now stretches approximately 65 feet in diameter.

A fire department official said on Thursday that the hole had deepened, and that the front section of the truck, where the driver is believed to be trapped, was no longer visible. “The situation is extremely dangerous, and we can’t send many rescuers,” he said. “We will try to rescue him as soon as possible.”

Firefighters are considering the use of heavy machinery to clear the dirt and debris in order to access the trapped driver. On Wednesday, a large crane was able to lift part of the truck’s cargo bed to the surface, but the driver was not found in that section of the vehicle.

Local authorities said the collapse was triggered by a burst sewer pipe under the road that transports wastewater to a nearby treatment facility. The damage to the pipeline has prompted the prefecture to issue a directive for 1.2 million residents in the area to refrain from using water.

Routine inspections of the sewer system under the road, conducted every five years, did not indicate any immediate need for repairs, according to an official in Saitama. In the most recent inspection, conducted in fiscal year 2021, some corrosion was detected, but it was not deemed an urgent issue, he said.

In response to the incident, Japan’s Ministry of Land, Infrastructure, Transport and Tourism said it has called for emergency inspections of similar infrastructure, particularly those connected to large-scale wastewater treatment plants.