In the heart of Chicago’s Loop, 90 years apart, two very different disasters took place. First, the deadliest building fire in U.S. history: the 1903 Iroquois Theater Fire. Caused by hasty construction, missing and faulty safety features, and a botched evacuation, the tragedy shocked the nation and gave rise to many safeguards still in place today. Then, the Great Loop Flood of 1992: a $2 billion disaster with zero casualties. As downtown buildings mysteriously flooded with water – and fish – from the Chicago River, the city searched for answers in a long-forgotten tunnel system.