Watch Modern Marvels online: Episode 15 Deadliest Weapons

In this fiery hour, we profile five of the world's deadliest weapons, focusing on the inventors, battles, and dark technology behind their lethality. Beginning with the deadliest bomb ever created, the Tsar Bomba--a 50-megaton nuclear bomb--we move on to the deadliest weapons ever used on people, the atomic bombs exploded over Hiroshima and Nagasaki in August 1945. During WWI, the machine gun led to the deaths of over 8-million, and in WWII, the use of incendiary bombs killed hundreds of thousands of people. Another deadly invention of WWII was the proximity fuse, or VT fuse, that allowed artillery to detonate within a predetermined range of an enemy target. Finally, we examine VX nerve gas--a deadly chemical agent used twice by Saddam Hussein with devastating results--and visit Edgewood Chemical BioCenter, where suspicious items in the current war in Iraq are examined for traces of VX.

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