|Fig. 1: The lost Mark IV bomb the diver thought he discovered. (Source: Wikimedia Commons)|
On November 24, 2016 a Canadian diver off the coast of British Columbia came across what he supposed was a "lost nuke." The object in question was thought to be the Mark IV, an American bomb that disappeared after a B-36 bomber crashed in 1950. During the simulation, 3 of the plane's engines caught on fire, requiring the crew to abandon the bomber. The United States Air Force claims the nuke was ejected over the Pacific, never to be seen again. The U.S. government, however, believes the object in question is actually a fake bomb. Conversely, Smyrichinskya's account of the unidentified object matches the description of a real bomb, leaving many in fear of danger of an unexploded nuclear bomb nearby.  While these recent events are alarming, they are not uncommon. Due to the high levels of secrecy surrounding nuclear power, especially during the Cold War, there are several cases of missing bombs that still baffle military historians and concern citizens to this day. 
A fake nuke is shaped very similarly to real nukes, making it difficult to distinguish one from the other. Their contents are extremely different, however. Real nukes, such as the one seen in Fig. 1, are made of plutonium. The B-36's fake nukes were packed with lead, uranium, and TNT.  The government does not believe the bomb contains any active nuclear material, but that does not make it entirely safe.
A broken arrow is as an accidental event such as misplacing, firing, detonating, or losing a nuclear weapon. Such events are not uncommon- at least 32 broken arrows occured between 1945 and 2007.  Many of these weapons were similar to this situation and were dropped in the ocean, never to be recovered. The pinnacle of broken arrow cases occurred in the 1950's and 1960's which is expected in light of the Cold War. The number of broken arrows have decreased since then. When such accidents occur, it is important to note whether real bombs or fake bombs were on board the devices which lost the bombs and whether those bombs still pose a threat.
There are many safety concerns revolving both the production of nuclear bombs and the preservation of them. Linda Thompson outlines the challenges relating to the storage of nuclear waste and the ways in which those challenges have been resolved over time.  It is important to take steps to safeguard nuclear bombs in the same way. Although numbers of broken arrows have decreased, it is still imperative that the United States actively pursue nuclear safety.
The Canadian government confirmed that the object in question is not the lost Mark IV. While it remains unidentified, it's presence and uproar the situation created confirms the government's need to protect its citizens against broken arrow cases.
© Caroline Beaudoin. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 C. Graham, "Missing Cold War Nuclear Bomb Remains a Mystery After Canadian Navy Investigates Object Found by Diver," The Telegraph, 26 Nov 16.
 R. Levinson-King, "Nuclear Weapon Missing Since 1950 'May Have Been Found'," BBC News, 7 Nov 16.
 K. Malone, "Broken Arrow Incidents," Physics 241, Stanford University, Winter 2011.
 L. Thompson, "Vitrification of Nuclear Waste," Physics 240, Stanford University, Fall 2010.