A tropical storm called Maysak has killed 39 people in southern China, with most deaths caused by a broken dam that flooded the city of Nanning. Ding Wei, a city official, announced the death count on Thursday Al Jazeera.

The number was much higher than earlier reports. State media had reported only six dead and eleven missing just days before, and Beijing had sent aid supplies to the region Xinhua english.www.gov.cn. When the storm started, officials said only two people had died. The death toll grew as floodwaters went down and rescue teams could reach people who had been trapped without help.

Maysak brought extreme rainfall to Guangxi starting Saturday, July 4, according to reports, and broke reservoirs that hold water behind dams AP via Washington Post. The BBC said heavy rain hit Renhe village by Sunday, July 5, and the storm even created rare tornadoes BBC. Weather officials measured rainfall of 10 to 40 centimeters across most areas, with some places getting more than 90 centimeters—roughly the height of a human.

About 130,000 people had to leave their homes as water rose. Rescue teams used more than 8,000 workers and roughly 5,700 boats to help people. By Thursday, water levels were going down, though more rain was expected in some areas. Electricity had been restored to more than 60,000 homes.

China's emergency officials warned the storm would keep affecting the country through Thursday, with rivers expected to rise significantly across the Pearl River basin, which drains toward the South China Sea iChongqing. The storm also brought heavy rain and flooding to Vietnam starting the same weekend AP.

At a local zoo in the region, flood damage to animal enclosures allowed at least 100 animals—including alpacas and zebras—to escape.

When disasters happen quickly, death counts often go up once rescue workers reach people who were cut off and once officials confirm exactly how people died. In this case, the dam failure—not just heavy rain—caused most deaths. This matters because it changes which officials might be held responsible once the immediate rescue is over.