See main article: Type 035 submarine. No. 361 was part of the 12th Submarine Brigade of the North Sea Fleet of the PLA Navy based at Lüshunkou in Liaoning Province. It was a Type 035G (Ming III-class) submarine. These were derivatives of Soviet Project 633 a.k.a Romeo-class submarines, which themselves were derivatives of German World War II advanced Type XXI diesel/electric U-boats.[2]
According to CNN, China was increasing training and exercises of its submarines in the east to carry out a policy of "sea denial" to counter the United States Pacific Fleet.[3]
According to the official Chinese news agency Xinhua, all 70 crew members died when the submarine's diesel engine used up all available oxygen (because it had failed to shut down properly) while the boat was submerged on April 16, 2003. The submarine, which was commanded by Commodore Cheng Fuming (Chinese: 程福明), had been taking part in naval exercises east of Inner Changshan Islands in the Yellow Sea off the coast of Northeastern China. Along with its normal complement, the crew included 13 trainee cadets from the Chinese naval academy.[4]
After the disaster, the crippled submarine drifted for ten days because it was on a silent, no-contact exercise. The boat was discovered by Chinese fishermen who noticed its periscope protruding above the surface on April 25, 2003. The crew were slumped over at their stations, seemingly having died before becoming aware of any issue.[5]
At a press conference on May 8, 2003, Foreign Ministry spokesperson Zhang Qiyue stated that while on an exercise east of Changshan Islands, the No. 361 submarine was incapacitated by a mechanical problem and all 70 on board had perished. The submarine had been towed to a port as of the time of the press conference.[6] The submarine was initially towed to Yulin Harbor near Sanya on Hainan Island before being taken back to the northeast seaport of Dalian in Liaoning province.
On May 2, 2003, Central Military Commission (CMC) chairman Jiang Zemin said in a condolence message to the families of the dead that "the officers and sailors of 361 remembered their sacred duty entrusted to them by the Party and the people. They died on duty, sacrificed themselves for the country, and they are great losses to the People’s Navy."[7]
CMC Vice-chairman Guo Boxiong led an inquiry into the incident, which resulted in the dismissal or demotion of five senior PLA Navy officers in June 2003: Navy Commander Shi Yunsheng (replaced by Zhang Dingfa) and Political Commissar Yang Huaiqing; North Sea Fleet Commander Ding Yiping, Political Commissar Chen Xianfeng (Chinese: 陈先锋), and Chief of Staff Xiao Xinnian.[8] Ding Yiping had been groomed to be the candidate for Navy Commander, but was removed from contention after the accident. Admiral Wu Shengli eventually succeeded Zhang Dingfa as Commander.[9]