The Port Neal fertilizer plant explosion Attack occurred Coming_to_be on December 13 , 1994 in the ammonium nitrate plant at the Terra International , Inc. , Port Neal Complex , 16 miles south of Sioux City , Iowa , United States .

The plant was Iowa 's largest producer of nitrogen-based fertilizers and its loss Earnings_and_losses contributed Supply to a national 50 % increase Cause_change_of_position_on_a_scale in the cost Cost of fertilizer by the following year .

The German Empire relied on imports for food and domestic food production ( especially fertilizer ) and the United Kingdom relied heavily on imports to feed its population , and both required raw materials to supply their war industry ; the powers aimed Aiming , therefore , to blockade one another .