41 years ago today, May 13, 1984 (April 13, 1984, lunar calendar), a Soviet stockpile of missiles exploded. On May 13, 1984, the US spy satellite discovered that a series of strong explosions suddenly occurred at an important base in North Murmansk on the Kola Peninsula of the Soviet Union under strict space surveillance. The flames lit up half of the sky and the sound spread. Tens of kilometers away, the explosion destroyed about two-thirds of the ship-to-air and ship-to-ship missiles stored here by the Soviet Northern Fleet, causing an unprecedented and serious damage to the combat effectiveness of the Northern Fleet. The Northern Fleet, based near Murmansk, is the most powerful of the four fleets of the Soviet Navy. It is spearheaded by an aircraft carrier that includes 148 cruisers, destroyers and other warships, as well as 190 of the Soviet Union's 371 submarines. Once war breaks out, the fleet will be responsible for controlling the Arctic Ocean, entering the Atlantic Ocean and conducting amphibious landing operations on NATO's northern flank. Because the Northern Fleet's combat tasks are quite heavy and there are constant exercises in peacetime, it is common to store too much ammunition and explosion accidents. In the past seven months, seven major ammunition explosions have occurred in Soviet military bases, including this base. However, the explosion was so strong that after seismic instruments recorded it, Western analysts suspected that it had "ignited one or more nuclear warheads." The explosion destroyed approximately 580 ship-to-air missiles, 320 ship-to-ship missiles, and 80 missiles capable of carrying nuclear warheads. It also damaged many different types of ship-to-ship and ship-to-air missiles. In addition, the explosion also damaged a large number of missile parts. The fire caused by the explosion burned for five days, creating a smoke cloud so thick that meteorological satellite observers reported it as "an unusual cloud." At least 200 Soviet naval personnel were killed and a similar number were injured in the explosion. U.S. spy satellites found that the places with the heaviest losses were the main missile storage site, explosive parts storage area, and the main ammunition depot about 1 kilometer from the main storage facility for submarine-launched ballistic missiles. Three of the six bunkers storing submarine-launched missiles had their surfaces damaged and debris was everywhere. Officials from Western intelligence agencies analyzed that the explosion was not a man-made sabotage activity, but was due to an "negligent accident." Before the explosion, the Soviet Union conducted maritime military exercises. For this exercise, a new batch of weapons was added to the ammunition depot, but the usual security measures were not followed. There were too many ammunition and placed too close. After the original ammunition depot exploded, it immediately caused a "chain explosion" in the entire ammunition depot group, which led to this major military disaster.