The K-84 Ekaterinburg submarine of the Project 667BDRM/Delta IV class caught fire on December 29, 2011. The submarine was undergoing repairs in the PD-50 floating dry dock in Roslyakovo, near Severomorsk, where it was moved earlier this month. The fire reportedly began at about 16:20 MSK at the wooden scaffolding and later moved to the outer hull of the submarine. Firefighters had to submerge the submarine to extinguish the fire. According to an official report, the fire was put out by 16:00 MSK on December 30, 2011.
The submarine reactors were shut down and various sources in the military insisted that ballistic missiles had been removed from the submarine. The fire damaged the outer hull of the submarine, so it might take a year or longer before the submarine could return to service.
UPDATE: The submarine will return to service no earlier than summer of 2014.