HIROSHIMA, Japan >> Rescuers were hard at work searching for dozens still missing in southwestern Japan on Monday after heavy rains that left residents returning to their homes speechless and unsure where to start the recovery and cleanup due to the extent of damage from flooding and mudslides.

At least 100 people died or are presumed dead, with more than 60 still unaccounted for, most of them in the hardest-hit Hiroshima area.

Seiji Toda was shocked and helpless when he saw his restaurant, which he opened nearly 40 years ago, filled with mud heaped about 1 meter (yards) from the floor. Tables, covered with clean white tablecloths before he left, were all mud-covered, chairs thrown to the floor.

“I had never seen anything like this,” he said on TBS television, standing outside his restaurant in Hiroshima city while wearing a helmet. He says it would be impossible to clean up the mess by hand.

Right next to his restaurant were heaps of broken trees and other debris. Several cars were still half buried in the mud.

The assessment of casualties has been difficult because of the widespread area affected by the rainfall, flooding and landslides since late last week. Authorities warned that landslides could strike even after rain subsides as the calamity shaped up to be potentially the worst in decades.

Some homes were smashed. Others were tilting precariously. Rivers overflowed, turning towns into lakes, leaving dozens of people stranded on rooftops. Military paddle boats and helicopters have brought people to the ground.

Chief Cabinet Secretary Yoshihide Suga said Monday that 87 people were confirmed dead and 13 others were without vital signs when they were found.

Prime Minsiter Shinzo Abe said the government has expended the search and rescue effort, dispatching 73,000 troops and emergency workers. “The rescue teams are doing their utmost.”

In large parts of Hiroshima, water streamed through a residential area, strewn with fallen telephone poles, uprooted trees and mud over the weekend.

Toda, the restaurant owner, said he took precautions because of his fresh memory of flooding four years ago that killed more than 70 in Hiroshima. Others were caught off guard.

“It gives me a chill thinking what could have happened,” said Eiko Yamane on Sunday as she recalled realizing how suddenly water was seeping the tires of the car she was driving. She was able to escape.

The Japan Meteorological Agency said three hours of rainfall in one area in Kochi prefecture reached an accumulated 26.3 centimeters (10.4 inches), the highest since such records started in 1976.

A couple was found dead in a farmhouse buried in a mudslide in Kagoshima prefecture Monday, while earlier a woman who was reported as missing after getting trapped in her car was found dead, Kyodo news service reported. Kochi prefecture, on Shikoku, issued landslide warnings almost over the entire island.

The Japanese government set up an emergency taskforce over the weekend and has sent troops, firefighters, police and other disaster relief. People have also taken to social media to plead for help.

Okayama prefecture, south of Hiroshima, said in a statement that five people had died, seven were missing and 11 were injured, at least one of them seriously. Nine homes were destroyed, dozens more were damaged, while more than 500 were flooded.