Rescuers in Japan are still trying to reach a truck driver who plunged into a sinkhole on Tuesday north of Tokyo. They plan to bring in heavy machinery to clear away masses of mud and debris.

Officials say they are making a slope into the cavity, which has a depth of about 15 meters. They say the work was more than half complete on Friday, and they hope to start using it within a few days.

The 74-year-old male driver plunged into the sinkhole when the ground suddenly gave way at an intersection in Yashio City, Saitama Prefecture.

Mud and debris are believed to have piled up as high as about eight meters.

Rain and other forms of water threatened to hinder the rescue operation. But officials say they've managed to stop it flowing into the hole.

On Friday, Saitama Governor Ono Motohiro announced plans to establish a special panel to find the cause of the sinkhole and prevent a recurrence.