MOSCOW, November 13 (RIA Novosti) - A crew member activated without permission a fire safety system on board the Russian nuclear submarine Nerpa, causing the deaths of 20 people, investigators said on Thursday.
"Military investigators have determined the person who activated, without permission or any particular grounds, a fire safety system on board the submarine. He is a sailor from the crew, and he has already confessed," said Vladimir Markin, a spokesman for the Investigation Committee of the Prosecutor General's Office.
Criminal charges have already been brought against the crew member, and he faces up to seven years in jail.
Meanwhile, an expert from the investigative commission said the probe must determine how the sailor managed to gain unauthorized access to the system.
"Only senior commanding officers have access to the fire safety system. It is impossible to simply activate the system, which is protected from unauthorized activation by multiple levels of confirmation," the official said.
"We must find out how a person without authorization managed to activate the system and determine whether the same situation could occur again," he said.
The tragedy occurred late on Saturday while the Nerpa was undergoing sea trials in the Sea of Japan. Three submariners and 17 shipyard workers died in the accident. There were 208 people, 81 of them submariners, on board the vessel at the time.
Investigators earlier established that the fire safety system that was thought to have malfunctioned was in order.
The submarine's reactor was not affected by the accident, which occurred in the nose of the vessel, and radiation levels on board remained normal.
The sub will resume sea trials after the conclusion of the investigation, a spokesperson for Russia's Amur Shipbuilding Plant said on Thursday.
"The Russian Navy has said it will still commission the submarine, therefore, the sea trials will continue after the investigation and certain technical adjustments. The previous shipyard team will participate in future trials," Marina Radayeva said.
The Nerpa started sea trials on October 27.
The incident is the worst for the Russian Navy since the sinking of the Kursk nuclear submarine in 2000 when all 118 sailors died.
The construction of the Akula II class Nerpa nuclear attack submarine started in 1991, but was suspended for over a decade due to a lack of funding. Akula II class vessels are considered the quietest and deadliest of all Russian nuclear-powered attack submarines.
Based in the Russian Far Eastern city of Komsomolsk-on-Amur, the Amur Shipbuilding Plant has built 270 vessels, including the Nerpa and another 55 nuclear submarines since it was established in 1936.