China’s military has blasted a dam to release floodwaters threatening one of its most heavily populated provinces, as the death toll in widespread flooding rose to at least 25. The dam operation was carried out late Tuesday night in the city of Luoyang, just as severe flooding overwhelmed the Henan provincial capital of Zhengzhou, trapping residents in the subway system and stranding them at schools, apartments and offices. Another seven people were reported missing, provincial officials said at a news conference. A video posted on Twitter by news site The Paper showed subway passengers standing in chest-high muddy brown water as torrents raged in the tunnel outside. Transport and work have been disrupted throughout the province, with rain turning streets into rapidly flowing rivers, washing away cars and rising into people’s homes. At least 10 trains carrying about 10,000 passengers were halted, including three for more than 40 hours, according to Caixin, a business news magazine. Sections of 26 highways were closed due to the rain, the Transport Ministry said on its social media account.