A report from FirstPost.India on the worst naval disaster in Indian history:
The Indian Navy suffered a huge blow Wednesday when a frontline submarine exploded and sank here at dawn with 18 sailors after two explosions turned it into a deadly ball of fire.
The deep sea attack vessel INS Sindhurakshak, recently refurbished in Russia, suffered an unexplained explosion just after Tuesday midnight and an immediate deafening blast heard almost in the whole of south Mumbai.
Naval officials said the rapid spread of the blaze and the intensity of the explosions left the trapped 18 sailors, including three officers, with apparently no chance of escaping.
“We cannot rule out sabotage,” navy chief Admiral D.K. Joshi told the media after Defence Minister A.K. Antony visited the disaster site at the Mumbai naval dock.
“But indications at this point do not support the (sabotage) theory,” he said. “At this point of time we are unable to put a finger on what exactly could have gone wrong.”
An inquiry set up to probe the disaster will submit its report within four weeks.
The most recent update to the Wikipedia page says:
On 14 August 2013, the Sindhurakshak sank after explosions caused by a fire took place onboard when the submarine was docked at Mumbai. The fire, followed by a series of ordnance blasts on the armed submarine, occurred shortly after midnight. The fire was put out within two hours. It is unclear exactly what caused the fire. Due to damage from the explosions, the submarine sank at its berth with only a portion visible above the water surface.[10][14][15] Sailors on board reportedly jumped off to safety. Navy divers were also brought in as there was a possibility that 18 personnel were trapped inside. India’s defence minister confirmed that there were fatalities.[6]
Due to the explosion, the front section of the submarine was twisted, bent and crumpled, and water had entered the forward compartment. Another submarine, INS Sindhuratna, also sustained minor damage when the fire on Sindhurakshak caused its torpedoes to explode.[14][16] Defence minister A. K. Antony briefed the Prime Minister Manmohan Singh on the submarine incident, and would leave for Mumbai to visit the accident site.[17][18]
Official sources said it was “highly unlikely” the submarine could be returned to service.[19]