New Delhi - One Indian worker was killed in an accident during construction of a nuclear submarine, a defence statement said Sunday, the latest in a string of deadly mishaps to hit the navy.Two other workers were injured in the accident on Saturday at a ship building centre in the southeastern coastal city of Vishakhapatnam, the Defence Research and Development Organisation statement said.An inquiry was under way into the incident which occurred when one of the hatches flew off and hit the contract workers during pressure testing of a part of the submarine, according to local media reports."One person, a contractual worker lost his life in the accident. Two others were injured and are under treatment," the organisation, which is charge of the construction project, said in the statement.The accident came just one day after a toxic gas leak on board the yet-to-be commissioned INS Kolkata naval ship killed an officer and injured two others during trials in Mumbai on Friday.The navy's chief resigned last month over another accident, a fire on board a submarine that killed two officers, during exercises off the Mumbai coast.The chief took responsibility for the accident which occurred after the deadliest incident in years, when the INS Sindurakshak burst into flames in Mumbai harbour last August, killing 18 sailors and sinking the vessel.Various other naval accidents reported in recent months included a submarine running aground in Mumbai's harbour, fires on a minesweeping vessel and an aircraft carrier, and a collision between a frigate and a fishing boat.Sunday's statement said "the submarines are safe and the accident does not adversely affect the project".India is building a number of Arihant-class nuclear-powered submarines, including the one on which the latest accident occurred, in an attempt to reduce its reliance on foreign suppliers.Defence experts say the navy has an ageing fleet and has struggled in the past with delays in the acquisition of new submarines and poor servicing.The 6,000-ton INS Arihant (Destroyer of Enemies) project was unveiled in 2009 to construct five such vessels which would be armed with nuclear-tipped missiles and torpedoes.According to reports, the first of the vessels is likely to be launched for sea trials within a couple of months and the others are expected to be completed this year.