HONG KONG—As floodwaters surged into a stalled subway prepare beneath the Chinese town of Zhengzhou, Pure Li hurriedly tapped out farewell messages to a close good friend on her smartphone. “I could not be ready to get out,” she wrote.

The 26-yr-aged engineer was one of extra than 500 passengers trapped during the evening rush hour Tuesday, as torrential rains pummeled the central province of Henan. A dozen persons wouldn’t make it out alive, authorities say, and at minimum two were being nonetheless missing as of Saturday early morning.

Determined photos from commuters surrounded by roiling h2o went viral on Chinese social media this 7 days, putting a nerve in a place that has vastly expanded its subway techniques, and experienced a sequence of significant underground flooding incidents that have raised security alarms.

On Thursday, China’s Ministry of Transportation purchased subway techniques nationwide to re-analyze and improve contingency designs for extreme weather. Authorities in Zhengzhou, Henan’s cash town, and Zhengzhou Metro Team, the state-owned subway corporation, did not reply to requests for comment.

As rain fell in Zhengzhou on Tuesday, turning streets into quickly flowing rivers and wreaking hundreds of millions of pounds of hurt, according to state media, h2o began to pool in a prepare yard, the metro corporation said in a statement. It then broke via a wall and flowed into a tunnel.