An explosion occurred in the ammonium nitrate process area of this plant. As a result of the explosion, the seven-story main process building was completely destroyed and a 30-foot-diameter crater was created. Metal fragments from the explosion punctured one of the plant’s two 15,000-metric-ton refrigerated ammonia storage tanks. The punctured tank released an estimated 5,700 metric tons of ammonia, causing the evacuation of approximately 2,500 people from the surrounding area. Metal fragments also punctured a nitric acid tank, resulting in the release of approximately 100 metric tons of this acid. The explosion tore metal siding from adjacent buildings, damaged three third-party electric generating stations, broke windows of buildings 16 miles away in Sioux City, and was felt more than 30 miles away.

[ Property Damage $203 Million. Estimated Current Value $404 Million ]

Image credit: EPA
Ref: https://en.wikipedia.org/wiki/Port_Neal_fertilizer_plant_explosion