Wang Zhiguo (L) does data analysis with colleagues at Nanjing Lukou International Airport in Nanjing, capital of east China's Jiangsu Province, Aug. 7, 2018. Wang Jicai, who used to be head of the militia post on Kaishan Island in Jiangsu Province, started working on the island in the Yellow Sea with his wife in 1986. He died of sudden illness while on duty in July of 2018 at the age of 58. Wang Zhiguo, son of Wang Jicai, became a frontier defence policeman after his graduation from Nanjing University of Aeronautics and Astronautics in 2013. He had been assigned to many security tasks for major events during 5 years' working. (Xinhua/Li Xiang)