Video footage captured how the inflatable castle was blown away in a matter of seconds as a woman clung in vain to its side in an attempt to hold it down. The incident occurred on June 4 in Tianyang City in the region of Guangxi, according to local reports.
The child, clearly visible inside the castle on the video, eventually fell and later died, the director of emergency treatment in Tianyang County's hospital told Chinese television.
"The child was in a coma when she came in for emergency treatment," he said. "We immediately began emergency treatment, cardio-pulmonary resuscitation, and asked surgeons for a consultation. About 40 minutes later, however, the child died."
Tianyang City police declined to comment on the incident, but according to state media the inflatable castle had been installed illegally in front of a local supermarket and was not properly anchored to the ground.
Local officials from Tianyang's work safety administration have declared the inflatable castle an unlicensed business and police were investigating the incident, China's Xinhua news agency reported.