In the biggest industrial disaster in US history, the entire city of Galveston, TX was destroyed Apr 16, 1947 when ammonium nitrate in the SS Grandcamp spontaneously ignited. Despite desperate efforts to extinguish the fire, she exploded, causing other ships, 1 with 4 million pounds of sulphur & ammonium nitrate to explode. 800 people died instantly. Anchors were found over a mile away. The explosion was felt 100 miles away. the entire harbor was levelled. Over a billion dollars in damage done.