Torrential rains have hit about half of China since Tuesday, leaving one dead, four injured and nearly 400,000 affected.
The rain also caused blocked traffic in cities, delayed flights, destroyed homes, flooded farmland and threatened flooding in river areas, mainly south of the Yangtze River.
Heavy rainstorm hit Kuming, capital city of southwest China's Yunnan Province, on July 2.
The casualties were reported in Shanghai, where a two-story building collapsed on Wednesday afternoon at a construction site and five construction workers were buried in debris.
Rescuers sent the workers to local hospital, but one of them Yue Hongbo, from central China's Henan Province, died later. Doctors said the other four were not in danger.
Police said heavy rain and strong winds led to the accident.
The atrocious weather also caused an hour-long power cut on the railway linking Shanghai and neighboring Hangzhou, leaving trains from Shanghai railway station delayed.
Shanghai's neighbors, Zhejiang and Anhui, both issued heavy rain warnings on Wednesday, telling local authorities to prepare for possible flooding and disasters and to strengthen patrols along dams and reservoirs.
Seven counties and cities in the central Hubei Province reported more than 395,900 people affected and 35,580 hectares of crops damaged.
Long Limin, chief expert with the provincial observatory, said the rainfall in Zhongxiang, Jingshan, Huangpi, Macheng, Hong'an, Xiaochang, Dawu all exceeded 100 millimeters with the maximum at 247 millimeters.
Macheng City, the worst-stricken area, received an average of 164 millimeters of rain in five hours on Wednesday, the most in 17 years.
The city's civil affairs bureau said more than 350,000 people were affected and 19,850 hectares of farmland flooded, leaving losses worth 16.55 million yuan (US$2.41 million).
Downtown areas in the southwestern city of Kunming, capital of Yunnan Province, were almost all flooded with up to a meter of water in places after a six-hour rainstorm over Tuesday night.
The city's traffic was seriously disrupted and many people complained they were late for work as the major avenues were all under water.
More seriously, some junior high students were late for the annual entrance examination to senior high school, which began on Wednesday, but local education authorities allowed latecomers to be given extra time.
The city's international airport was also closed on Tuesday morning as the runways were waist-deep in water. As of 7 PM, more than 150 flights were delayed and more than 3,500 passengers were stranded.
More than 20 flights to Kunming had to land in the neighboring municipality of Chongqing instead.
The airport reopened at 5 PM and flights to Beijing and Shanghai took off. However, at 8 p.m., more than 1,000 passengers waiting still stranded.
More rain was forecast in the next two days and the China Meteorological Administration asked local governments to prepare.