Typhoon Shanshan lashed southern Japan with record rainfall and powerful winds on Thursday, flooding towns, knocking out power to thousands of homes and forcing more than four million evacuations.

The storm, the strongest to hit Japan this year, packed maximum sustained winds of up to 75 miles per hour and gusts of 92 m.p.h. on Thursday evening, equivalent to those of a Category 1 hurricane, according to the U.S. Navy’s Joint Typhoon Warning Center.

Shanshan had peaked at Category-4 strength before making landfall around 8 a.m. on Kyushu, the southernmost of Japan’s main islands, according to the Japan Meteorological Agency. It was forecast to move north through Kyushu on Thursday, then shift east on Friday and Saturday, moving further inland and losing strength.

The storm was weakening as it moved slowly inland, but the authorities issued warnings for landslides and floods in many parts of southwestern Japan. More than 4.1 million people were under evacuation orders nationwide, Japan’s Cabinet Office said on Thursday.

“This is one of the biggest typhoons in recent years, for a prefecture that experiences many typhoons every year,” Kensei Tomisako, a disaster response official in Satsumasendai, said in an interview.

Shanshan has brought record rainfall. Some parts of Kyushu recorded 2.6 feet of rain in 48 hours, forecasters said. The storm, moving north at just 7 m.p.h. on Thursday afternoon, lashed some areas with rain for hours.

Three people died after a landslide on Tuesday buried their home in Gamagori, a city in central Japan that was hit by heavy rain, the local government said early Thursday.

More than 50 people were injured in the storm, and one person was missing, according to Japan’s public broadcaster, NHK. Almost 180,000 households were without power as of Thursday evening, service provider Kyushu Electric Power Transmission and Distribution said.

Japan Airlines, one of the country’s largest airlines, canceled all flights to and from Nagasaki and seven other cities in Shanshan’s path on Thursday and said that many flights to and from 20 cities across the country on Friday had already been canceled. All Nippon Airways also canceled all flights that had been scheduled at Kansai International Airport for Friday.

Shinkansen bullet-train service was suspended on Thursday for all of Kyushu. Many of the train lines linking major cities in western Japan, including Osaka, Kyoto and Hiroshima, were also suspended.

On Wednesday, the authorities issued rare emergency warnings for the storm in Kagoshima Prefecture, indicating that a large-scale disaster was possible, according to the Japan Meteorological Agency. The warnings were downgraded on Thursday morning.

Toyota announced that it would pause production at all 14 of its Japan factories starting Wednesday evening to protect its workers. On Thursday morning, the carmaker said that it would extend the suspension until Friday for all but one of the factories.