Shortly after 0530 Moscow time, seawater leaking into silo six of K-219 reacted with missile fuel, producing chlorine and nitrogen dioxide gases and sufficient heat to explosively decompose additional fuming nitric acid to produce more nitrogen dioxide gas.
K-219 weapons officer Alexander Petrachkov attempted to deal with this by disengaging the hatch cover and venting the missile tube to the sea.
Shortly after 0532, an explosion occurred in silo six.
K-219 had previously experienced a similar casualty; one of her missile tubes was already disabled and welded shut, having been permanently sealed after an explosion caused by reaction between seawater leaking into the silo and missile fuel residue.

An article in Undersea warfare by Captain First Rank (Ret.)
Igor Kurdin, Russian Navy – K-219's previous XO (executive officer) – and Lieutenant Commander Wayne Grasdock, USN described the explosion occurrence as follows:
At 0514, the BCh-2 officer and the hold machinist/engineer in compartment IV (the forward missile compartment) discovered water dripping from under the plug of missile tube No.
6 (the third tube from the bow on the port side).
During precompression of the plug, the drips turned into a stream.
The BCh-2 officer reported water in missile tube No.
6, and at 0525, the captain ordered an ascent to a safe depth (46 meters) while a pump was started in an attempt to dry out missile tube No.
6.
At 0532, brown clouds of oxidant began issuing from under the missile-tube plug, and the BCh-2 officer declared an accident alert in the compartment and reported the situation to the GKP (main control post).
Although personnel assigned to other compartments left the space, nine people remained in compartment IV.
The captain declared an accident alert.
It took the crew no more than one minute to carry out initial damage control measures, which included hermetically sealing all compartments.
Five minutes later, at 0538, an explosion occurred in missile tube No.
6.

Two sailors were killed outright in the explosion, and a third died soon afterward from toxic gas poisoning.
Through a breach in the hull, the vessel immediately started taking on sea water, quickly sinking from its original depth of 40 metres (130 ft) to eventually reach a depth in excess of 300 metres (980 ft).
Sealing of all of the compartments and full engagement of the sea water pumps in the stricken compartments enabled the depth to be stabilised.

Up to 25 sailors were trapped in a sealed section, and it was only after a conference with his incident specialists that the Captain allowed the Chief Engineer to open the hatch and save the 25 lives.
It could be seen from instruments that although the nuclear reactor should have automatically been shut down, it was not.
Lt.
Nikolai Belikov, one of the reactor control officers, entered the reactor compartment but ran out of oxygen after turning just one of the four rod assemblies on the first reactor.
 Twenty-year-old enlisted seaman Sergei Preminin then volunteered to shut down the reactor by following the instructions of the Chief Engineer.
Working with a full-face gas mask, he successfully shut down the reactor.
A large fire had developed within the compartment, raising the pressure.
When Preminin tried to reach his comrades on the other side of a door, the pressure difference prevented him from opening it, and he subsequently died of asphyxiation in the reactor compartment.

In a nuclear safe condition, and with sufficient stability to allow it to surface, Captain Britanov surfaced K-219 on battery power alone.
He was then ordered to have the ship towed by a Soviet freighter back to her home port of Gadzhiyevo, 7,000 kilometres (4,300 mi) away.
Although a towline was attached, towing attempts were unsuccessful, and after subsequent poison gas leaks into the final aft compartments and against orders, Britanov ordered the crew to evacuate onto the towing ship, but remained aboard K-219 himself.

Displeased with Britanov's inability to repair his submarine and continue his patrol, Moscow ordered Valery Pshenichny, K-219’s s
Shortly after 0530 Moscow time, seawater leaking into silo six of K-219 reacted with missile fuel, producing chlorine and nitrogen dioxide gases and sufficient heat to explosively decompose additional fuming nitric acid to produce more nitrogen dioxide gas. K-219 weapons officer Alexander Petrachkov attempted to deal with this by disengaging the hatch cover and venting the missile tube to the sea. Shortly after 0532, an explosion occurred in silo six. K-219 had previously experienced a similar casualty; one of her missile tubes was already disabled and welded shut, having been permanently sealed after an explosion caused by reaction between seawater leaking into the silo and missile fuel residue.
An article in Undersea warfare by Captain First Rank (Ret.) Igor Kurdin, Russian Navy – K-219's previous XO (executive officer) – and Lieutenant Commander Wayne Grasdock, USN described the explosion occurrence as follows:
At 0514, the BCh-2 officer and the hold machinist/engineer in compartment IV (the forward missile compartment) discovered water dripping from under the plug of missile tube No. 6 (the third tube from the bow on the port side). During precompression of the plug, the drips turned into a stream. The BCh-2 officer reported water in missile tube No. 6, and at 0525, the captain ordered an ascent to a safe depth (46 meters) while a pump was started in an attempt to dry out missile tube No. 6. At 0532, brown clouds of oxidant began issuing from under the missile-tube plug, and the BCh-2 officer declared an accident alert in the compartment and reported the situation to the GKP (main control post). Although personnel assigned to other compartments left the space, nine people remained in compartment IV. The captain declared an accident alert. It took the crew no more than one minute to carry out initial damage control measures, which included hermetically sealing all compartments. Five minutes later, at 0538, an explosion occurred in missile tube No. 6.
Two sailors were killed outright in the explosion, and a third died soon afterward from toxic gas poisoning. Through a breach in the hull, the vessel immediately started taking on sea water, quickly sinking from its original depth of 40 metres (130 ft) to eventually reach a depth in excess of 300 metres (980 ft). Sealing of all of the compartments and full engagement of the sea water pumps in the stricken compartments enabled the depth to be stabilised.
Up to 25 sailors were trapped in a sealed section, and it was only after a conference with his incident specialists that the Captain allowed the Chief Engineer to open the hatch and save the 25 lives. It could be seen from instruments that although the nuclear reactor should have automatically been shut down, it was not. Lt. Nikolai Belikov, one of the reactor control officers, entered the reactor compartment but ran out of oxygen after turning just one of the four rod assemblies on the first reactor.  Twenty-year-old enlisted seaman Sergei Preminin then volunteered to shut down the reactor by following the instructions of the Chief Engineer. Working with a full-face gas mask, he successfully shut down the reactor. A large fire had developed within the compartment, raising the pressure. When Preminin tried to reach his comrades on the other side of a door, the pressure difference prevented him from opening it, and he subsequently died of asphyxiation in the reactor compartment.
In a nuclear safe condition, and with sufficient stability to allow it to surface, Captain Britanov surfaced K-219 on battery power alone. He was then ordered to have the ship towed by a Soviet freighter back to her home port of Gadzhiyevo, 7,000 kilometres (4,300 mi) away. Although a towline was attached, towing attempts were unsuccessful, and after subsequent poison gas leaks into the final aft compartments and against orders, Britanov ordered the crew to evacuate onto the towing ship, but remained aboard K-219 himself.
Displeased with Britanov's inability to repair his submarine and continue his patrol, Moscow ordered Valery Pshenichny, K-219’s s
Soviet submarine K-219