In 2011, a Russian submarine was close to nuclear disaster in drydock

Kyle Mizokami for Popular Mechanics:

Russian Deputy Prime Minister Dmitri Rogozin has admitted that a December 2011 incident involving a nuclear missile submarine almost became one of the worst nuclear weapons disasters ever recorded.

The Ekaterinburg, a ballistic missile submarine, caught fire in drydock, threatening its load of liquid-fueled nuclear missiles. If the missiles had caught fire, then the resulting explosions would have spewed radioactivity over a wide area, threatening a nearby town of 300,000 people.

There are many reasons for unloading a ship’s weapons before docking, and this is one of them.