The Brooklyn Bridge stands as a timeless monument to 19th-century ingenuity, a majestic web of steel wire suspending a road over the treacherous East River. But beneath its soaring Gothic towers lies a dark, submerged history of unimaginable physical suffering and terrifying medical mystery. To anchor the bridge's massive stone towers, workers had to excavate the riverbed inside enormous, compressed-air wooden boxes called caissons. As they toiled in these claustrophobic, high-pressure chambers, they began to emerge with bizarre, agonizing symptoms: debilitating joint pain, paralysis, and sudden death. The medical world was baffled by what they termed "caisson disease." This book ventures into the murky, pressurized depths of the East River to uncover the truth behind decompression sickness. You will learn how nitrogen bubbles quietly destroyed the bodies of the "sandhogs," how chief engineer Washington Roebling was paralyzed by the very phenomenon he helped create, and how this tragedy forced the birth of modern hyperbaric medicine. Uncover the heavy human toll buried beneath a celebrated architectural triumph. By understanding the physics of the caisson, you will grasp the terrifying sacrifices made to build the modern metropolis.