Three officers are believed to be among the 18 men who met a tragic watery grave after a deafening blast tore through INS Sindhurakshak, which was berthed in the naval dockyard off Mumbai Harbour, offcials said.
The cause of the roaring explosion, heard over a two kilometre radius including large parts of south Mumbai, and the blaze that gutted the deep sea fighter vessel is still not known.
The sailors were reportedly working inside the submarine at the time of the incident and remained trapped till the submarine began sinking and finally went down around dawn.
TV grabs of the incident and amateur video shots showed a huge ball of flame erupting on the horizon of the Mumbai harbour and lasting for nearly three hours before it was brought under control around 3 a.m.
An alert Mumbai Fire Brigade managed to save a second submarine.
Deputy Chief Fire Officer P.S. Rahandale told IANS that he saw another submarine berthed barely five-six metres away from the burning INS Sindhurakshak.
Realising the danger, Rahandale alerted his fire figthers and those from the Indian Navy and Mumbai Port Trust to save that submarine.
"We built a wall of water-jets between INS Sindhurakshak and the other vessel, thereby giving it a safe window to sail to safety," he said.
In his first reaction, a grim Defence Minister A.K. Antony told the media in New Delhi: "I feel sad about those navy personnel who lost their lives for the country." He did not give the number of dead.
Antony then flew to Mumbai and visited the site.
The naval docks, the Mumbai Port Trust and the Jawaharlal Nehru Port Trust share a common navigation channel in Mumbai harbour through which the vessels belonging to all the three sail in and out.
An inquiry has been ordered into the disaster on the eve of India's 67th Independence Day.
INS Sindhurakshak was a diesel-electric submarine that returned home last year after a major refit at Russia's Zvezdochka shipyard.
It displaces 2,300 tonnes, carries 52 crew members, has a top speed of 19 knots (35 km per hour) and diving depth of 300 metres.
Its loss came barely two days after India acquired its first indigenous aircraft carrier INS Vikrant and the nuclear reactor that propels Arihant, the country's first ballistic missile submarine, went critical Aug 9.
The incident has dealt a major blow to Indian Navy, which has grown tremendously in recent decades with a view to dominate the Indian Ocean region by acquiring blue water operational capability.
With over 58,000 personnel, the Indian Navy boasts of a large operational fleet that includes an aircraft carrier, an amphibious transport vessel, eight guided missile destroyers, 15 frigates, a nuclear powered submarine, 14 conventional submarines, 24 corvettes, 30 patrol vessels, seven mine counter measure vessels and auxiliary ships.
INS Sindhurakshak was laid down in one of Russia's oldest shipyards, the Admiralty Wherf yard in St. Petersburg, in 1995. It was launched in 1997 and delivered to India in December that year.
The contract for its refit and modernization was signed in June 2010.
Part of the refit involved installation of equipment for Klub-S (3M54E1 anti-ship and 3M14E land attack) cruise missiles and over 10 Indian and foreign-made systems, including the Ushus hydro-acoustic (sonar) system and CSS-MK-2 radio communications system.
In addition, the boat's cooling system was modified, a "Porpoise" radio-locater fitted and other work carried out to increase the boat's military capacity and safety.
--IANS (Posted on 14-08-2013)