Indian Navy personnel tried all through Thursday, in vain, to enter 'INS Sindhurakshak', the submarine which sank with 18 crew in three metres of water at the Colaba naval dock after a series of blasts nearly 48 hours ago, reports 'The Times of India'. A large amount of muddy seawater had entered the diesel-powered Kilo class submarine, hampering visibility, and the heat of the explosion had melted parts of the 16-year-old vessel's internal hull, deforming its hatches and preventing access to compartments reports 'The Times of India' citing India Navy sources.