A naval accident you might not know about.  //

Apparently, the motor consumed most of the submarine’s air supply in just two minutes. The crew might have felt light headed and short of breath during the first minute, and would have begun losing consciousness in the second. The negative air pressure also made it impossible to open the hatches. A 2013 article by Reuters repeats this theory as well as mentioning the possibility that was exhaust was improperly vented back into the hull to fatal effect.

Any of these explanations would reflect serious failings in both crew training and mechanical performance.

The recent tragic loss of the Argentine submarine San Juan, the fire raging amongst moored Russian Kilo-class submarines at Vladivostok (a drill, Moscow claims), and the fortunately nonfatal but highly expensive flooding of the Indian nuclear-powered submarine Arihant highlight that despite being arguably the most fearsome weapon system on the planet, submarines remain dangerous to operate even when not engaged in a war. Even brief breakdowns in crew discipline or mechanical reliability can rapidly turn the stealthy underwater marauders into watery coffins.

Only high standards of maintenance, manufacturing and crew training can avert lethal peacetime disasters—standards which are difficult for many nations to afford, but which the PLA Navy likely aspires to it as it continues to expand and professionalize its forces at an extraordinary rate.