Two United Nations peacekeepers from China were killed after an attack in South Sudan on July 10. Five others were wounded, with two in serious condition. The incident came a little over a month after a Chinese U.N. peacekeeper was killed and four others wounded in an attack in northern Mali by al-Qaeda’s North Africa branch.

Li Lei, a 22-year-old soldier from Chengdu, was one of the victims of the most recent attack. Li's relatives and friends are grieving over his death. Li is the 13th peacekeeper who has died during China's 26 years of participation in the U.N.'s peacekeeping operation. Li died just one day after his 22nd birthday. "I hope all my comrades-in-arms will stay safe," was the last sentence Li recorded on social media.

Li Lei's honor certificate.

Praised by his relatives as a diligent and sensible boy, Li always went out of his way to help his family while he was on leave. Before he left for South Sudan, he told his mother that he hoped to toughen himself up on the frontlines. Li's mother has not stopped crying since she learned of her beloved son's death.

Li's former teacher, surnamed Jiang, remembers being very impressed by him. The brave, responsible student won the respect and admiration of all his classmates. One day Li told Jiang that he planned to drop out of school and join the army. Jiang tried and failed to dissuade him, all too aware that he was just hoping to ease his family's economic burden.

Li Lei and his grandmother.

On Monday, Li's belongings were displayed in front of his house to help his friends and relatives mourn. His military honors and exploits were clear proof of an excellent soldier, and therefore a source of comfort to his loved ones.

"We are all passing by each other. I hope you won't miss me when I'm gone. I never regret my choice," Li wrote in his diary before his death.