As heavy flooding takes over eastern Japan, houses were washed away and residents were forced to their rooftops, desperate for rescue by military helicopters.

The raging brown floodwaters spawned from Typhoon Etau, which has dumped 60 centimeters (2 feet) of rain over some areas recently.

Combine that with several weeks of near-daily rainfall, and Ibaraki and Tochigi prefectures are now deluged and unrecognizable.

“Tochigi Prefecture is facing a grave danger and is in an emergency situation,” Japan Meteorological Agency Spokesman Takuya Deshimaru said. “It is experiencing unprecedented downpour.”

More than 170,000 people have been evacuated, officials said. Those who didn’t leave found their houses submerged within minutes.

Members of the Japanese Self Defense Forces dropped from helicopter lines to pluck stranded residents from their roofs. Two by two, they swung precariously over the raging currents as they were pulled back up to the aircraft.

The Self Defense Forces had rescued 101 people by Thursday afternoon, a spokesman said.