At least 25 people have died from heavy rains in China's central province of Henan. Twelve of them died in a flooded underground train in Henan's capital, Zhengzhou.
Officials had to provide shelter for about 100,000 people in Zhengzhou. The floods stopped the city's rail and road transportation. Thousands of military troops have started a rescue effort in the area.
City officials said rescuers pulled more than 500 people to safety from the flooded subway. Social media images showed people who were riding the subway walking through deep waters in the dark. One subway station looked like a brown lake.
"The water reached my chest," one flood survivor wrote on social media. "I was really scared."
A local person whose family name is Guo said he had to spend the night at his office. Guo added that the rain stopped bus services in Zhengzhou.
"That's why many people took the subway, and the tragedy happened," Guo told Reuters.
At a news conference on Wednesday, officials said at least 25 people have died and seven remained missing since last weekend.
More rain is predicted across Henan for the next three days.
From last Saturday to Tuesday, 617.1 millimeters of rain fell in Zhengzhou. That is close to its yearly average rainfall of 640.8 millimeters.
The three days of rain equaled a level seen only "once in a thousand years," local weather broadcasters said.
Scientists told the Reuters news agency that the rainfall in China was likely linked to worldwide climate change, just like recent heat waves in the United States and Canada and extreme flooding seen in Western Europe.
Johnny Chan is a professor of atmospheric science at City University of Hong Kong. He said, "Such extreme weather events will likely become more frequent in the future."
He added that local and national governments must develop ways "to adapt to such changes."
'Flood prevention difficult'
Henan is a major center of transport with a population of about 100 million. Many train services in the area have had to stop. On one train just outside the city limits of Zhengzhou, hundreds of people have been trapped for two days with little food or water. Major roads were severely flooded in many cities of the province. Flights have been delayed or canceled.
In a statement broadcast by state television, Chinese President Xi Jinping said, "Flood prevention efforts have become very difficult."
Schools, hospitals cut off
Some schools and hospitals in Henan were trapped by floodwaters. People caught in the floods sought shelter in places like libraries, movie theaters and museums.
"We've up to 200 people of all ages seeking temporary shelter," a worker at the Zhengzhou Science and Technology Museum said.
"We've provided them with instant noodles and hot water. They spent the night in a huge meeting room," added the museum worker, whose family name is Wang.
The First Affiliated Hospital of Zhengzhou is the city's largest hospital. After it lost all power, officials tried to find transport for about 600 severely ill patients.
郑州市第一附属医院是郑州市最大的医院。在医院停电后，有关官员试图转运大约 600 名重症患者。
I'm Jill Robbins.