Check a Jane's fighting ships and you may be able to get something close to the actual figures. MSNBC has an article on it which can be read HERE
Apparently, it was a Ming class diesel submarine, an obsolecent design based on the old Soviet Romeo class boats. Frankly, I'm stunned that the Chinese even announced it. They're not known for advertising their mistakes to the world.
Information on the MING Class subs can be found HERE. According to the latest information on the CargoLaw Website The Peoples Liberation Army Navy (PLAN) is claiming the following; "suffered unidentified mechanical accident (likely a torpedo running on the rack) during drill near the Neichangshan islands off E. Shandong province in Bo Hei Sea -- 70 dead."
Okay, a hot run torpedo on the rack is not a good thing, but one wonders what sequence here killed the crew yet made it possible to recover the sub. (Better yet, made it possible for there to be a sub to recover!)
Chalk it up to my ever suspicious nature, but something here doesn't smell quite right.