At 5:16 a.m. on Friday, Feb. 13, 1981, an explosion in downtown Louisville, Ky., hurled a passenger car into a railroad overpass structure and dropped it into a crater. At the same time, officers in a police helicopter saw a series of explosions begin at the railroad underpass on Hill Street (three miles northwest of the Kentucky Exposition Center site) and continue along the streets of Old Louisville.The cause was the ignition of highly volatile hexane from a Ralston Purina soybean processing plant that escaped into the city sewer system. The explosion demolished more than 13 miles of lines in
