ISIS hammered as US drops biggest non-nuclear weapon ever: 21,000lb bomb is used in anger for the first time to obliterate jihadists' caves in Afghanistan. U.S. dropped its largest non-nuclear weapon after targeting ISIS tunnels in Afghanistan The blast in eastern Afghanistan killed 36 militants, according to the Afghan Ministry of Defense The GBU-43 bomb weighs 21,600 pounds, is 30 feet long, contains 11 tons of explosives and carries a mile-wide blast radius