At around 9:15am on the 27th of May, 1983, on a farm near Benton, Tennessee a powerful explosion took place. The blast was heard more than 32 kilometres (or 20 miles) away, and created a mushroom cloud the height of a six storey building. The site was all but levelled by the blast, and many workers present were instantly killed. But what could have caused a blast of such magnitude on a small, unassuming fishbait farm in rural Tennessee?