Through the case study of the waterproofing renovation project on the roof of Building 9 in Shengxin Community, this article explores the safety issues that may be encountered during the renovation process of old urban communities. During the construction process, due to inadequate safety measures, stones fell from the roof and damaged the flower pot of Mr. Wang, an elderly man living alone on the first floor, triggering an alarm. Community police officer Xiao Shang and the person in charge of the construction party confirmed the cause of the accident through on-site investigation, and proposed rectification requirements to the construction party in accordance with relevant laws and regulations. At the same time, Xiaoshang also explained in detail to Grandpa Wang the legal responsibility for high-altitude throwing, helping him understand that although the behavior of the construction party was dangerous, it did not constitute a crime. In the end, the construction party compensated Mr. Wang for his losses and promised to strengthen safety management. This case reflects the safety issues that need to be taken seriously in the renovation of old urban communities, as well as the professionalism and patience of community police officers in dealing with such issues.