At least six people have died, one is missing, and thousands of travelers have been stranded as unprecedented rainfall hit Chiba Prefecture, east of Tokyo in Japan, causing widespread flooding and severe disruption to transportation.

In some areas of Chiba, more than 360 millimeters of rain fell in just 24 hours, during one of Japan’s busiest holiday periods. In Chiba City, 115 millimeters of rain fell in one hour, while Sakura recorded 97 millimeters—both amounts were records for the two areas.

On Thursday, the Japan Meteorological Agency issued, for the first time, its highest-level warning for heavy rainfall in more than a dozen municipalities across the prefecture. The warning was downgraded on Friday as the weather conditions weakened, but authorities warned that the danger had not passed.

Meteorologist Takuya Hosomi described the rainfall levels in Chiba as unprecedented, while the prefecture’s governor, Toshihito Kumagai, described the situation as extremely unusual even by Japanese standards. “I have dealt with many disasters in the past, but I have never experienced a situation like this,” he said.

The floods claimed the lives of at least six people. A man was found floating in a flooded street in Ichikawa, while a 66-year-old woman died after her car became trapped in floodwaters in the city of Sakura. Another person was pulled from a flooded vehicle in Kashiwa and is believed to be dead, while one person remains missing. Soldiers have been deployed to the affected areas to assist with disaster-response operations.

Images broadcast by NHK illustrate the severity of the weather, showing water being propelled with enormous force from what appears to be a manhole in central Chiba, reaching a height greater than a nearby five-story building.

More than 80 homes were flooded, while nearly 230,000 residents across the prefecture were urged to evacuate their homes for safety reasons.

Meanwhile, around 23,000 households remained without electricity on Friday morning, down from 68,000 earlier, according to TEPCO Power Grid.

A night at the airport for 7,000 travelers

Chaos also prevailed at Narita International Airport, where around 7,000 people were forced to spend the night after flooding caused severe problems with road and rail connections to Tokyo. Travelers waited in lines to receive blankets, water and snacks from airport staff and then slept in various areas of the terminals.

“We will never forget this trip,” an American tourist who was stranded at the airport with his family told NHK.

Thousands of people found themselves in similar situations elsewhere. The Japan Ground Self-Defense Force sent buses to evacuate around 4,000 people who had spent the night at Soga Station, on the line serving Tokyo Disney Resort. The theme park reported no damage.

Hundreds of other residents sought shelter in the Chiba Prefectural Government building, where they spent the night sleeping under thermal blankets.

By Friday morning, some railway lines connecting Narita with Tokyo had resumed service, helping to ease congestion at the airport. Several lines, however, remained out of service.

Major roads in Chiba also remained closed, including routes connecting Narita with central Tokyo, forcing drivers to use alternative routes.

Despite the disruption, an airport representative said Friday’s flights were scheduled to operate normally. Japan Airlines warned of possible delays, but clarified that cancellations were not expected.