The Russian Akula II SSN (nuclear attack submarine) Nerpa, built for India, has finally completed its sea trials and was accepted into Russian service. But this will be temporary, as India is supposed to take possession in five months. The Indian crew for the sub has been ready for over a year now, Most of the delay arose 13 months ago, when, while undergoing sea trials, there was an accidental activation of the fire extinguisher system. This killed twenty sailors and civilians, and injured more than twenty. There were 208 people aboard the sub at the time, most of them navy and shipyard personnel there to closely monitor all aspects of the sub as it made its first dives and other maneuvers. The source of the fatal accident was poor design and construction of the safety systems on the sub. This accident led to sailors and shipyard technicians being fearful of going to sea on the boat. So the sea trials were delayed, even after repairs were made.
Once in Indian service, the Nerpa will be called the INS Chakra (the same name used by the Charlie class Russian sub India leased from 1988-91). The post-accident modifications on the Nerpa cost $65 million. The lease arrangement has India paying $178,000 a day, for ten years, for use of the sub. The 7,000 ton Akula IIs requires a crew of 51 highly trained sailors. It was Indian money that enabled Russia to complete construction on at least two Akulas. These boats were less than half finished at the end of the Cold War. This was another aftereffect of the collapse of the Soviet Union. Several major shipbuilding projects were basically put on hold (which still cost a lot of money), in the hopes that something would turn up. In this case, it was Indians with lots of cash. The Indian crew was, apparently, to take possession of the INS Chakra last Summer, and take it back to India. But this won't happen until May.
Traditionally, when a new ship losses lots of people during sea trials, it is regarded as "cursed" and unlucky. Sailors can be a superstitious, especially when there are dead bodies involved. It's not known if India will have any problems with this.